On the back of our last $500 motherboard review, it was clear that a number of readers were surprised that a mainstream motherboard could cost so much. We took the opportunity to ask ASUS why such a thing exists, especially when a high-end desktop platform combination could cost less. The answer is due to the engineering: an ROG motherboard takes twice as long to design and validate, as well as custom ICs and finding the secret sauce to each platform. ASUS said that they have platforms for any budget, but for the users who want to squeeze every last morsel of performance in a mainstream halo budget, they have a product for that as well. That product is the Maximus VIII Extreme, and this is our review.

Other AnandTech Reviews for Intel’s 6^th Generation CPUs and 100-Series Motherboards

Skylake-K Review: Core i7-6700K and Core i5-6600K - CPU Review
Comparison between the i7-6700K and i7-2600K in Bench - CPU Comparison
Overclocking Performance Mini-Test to 4.8 GHz - Overclocking
Skylake Architecture Analysis - Microarchitecture
Z170 Chipset Analysis and 55+ Motherboards - Motherboard Overview
Discrete Graphics: An Update for Z170 Motherboards - PCIe Firmware Update
Price Check: Intel Skylake i7-6700K and i5-6600K - Latest Skylake Price Check (3/29)

100-Series Motherboard Reviews:
Prices Correct at time of each review

($500) The GIGABYTE Z170X-Gaming G1 Review
($500) The ASUS Maximus VIII Extreme Review (this review)
($250) The ASUS Maximus VIII Impact Review
($240) The ASRock Z170 Extreme7+ Review
($230) The MSI Z170 Gaming M7 Review
($208) The GIGABYTE Z170-UD5 TH Review
($165) The ASUS Z170-A Review
($125) The Supermicro C7H170-M Review

To read specifically about the Z170 chip/platform and the specifications therein, our deep dive into what it is can be found at this link.

ASUS Maximus VIII Extreme Overview

As we mentioned in the Z170X-Gaming G1 review, for Intel’s Skylake platform, $500 is a large chunk of pie from any PC build, especially as users tend to focus on graphics, processor and/or storage before thinking about the motherboard. The cost of an i7-6700K (~$350 MSRP) plus a $500 motherboard comes in at $850 MSRP, compared to the six-core i7-5820K plus a $250 motherboard which is more around $550 MSRP, meaning that a cost-limited build would be exchanging two cores and $300 for motherboard features. But similar to the high-end Aston Martin One-77, coming in at $1.2 million, there are Astons under six figures. The number of One-77 vehicles sold is comparatively low, but it stands out as a halo product in the range, as does the Gaming G1 and the Maximus VIII Extreme (M8E).

I’ve known some readers to dismiss the car analogy, just because building a computer is different, especially when building a PC is modular whereas a car is purchased pre-built. Typically the Extreme models of ASUS’ ROG line sell rather well with system integrators in pre-built systems who will often pair a selected processor binned for high frequency and water cooling: users buying these systems are not necessarily worrying too much about cost, but are wanting the halo product and pushing it to the limit.

The M8E testing came at an interesting time in our workflow. Having just reviewed the main competition, it was clear that the M8E and Gaming G1 were trading blows with some features: for example, there is no PLX8747 chip on the M8E for tri-SLI support, but it does come with the now perennial OC Panel and tri-stream (3T3R) dual band Wi-Fi. The ASUS comes with a U.2 port, M.2 slot and four USB 3.1 ports, whereas the GIGABYTE gets HDMI 2.0, dual USB 3.1 and dual M.2 slots. The ASUS has custom TPU/EPU chips and an ESS audio DAC, whereas the GIGABYTE has PCIe guard plates and a Creative Core 3D codec and a Burr Brown OPA2132 OP-AMP. ASUS uses an Intel I219-V network port with LANGuard, the GIGABYTE gets dual Killer network points. Both systems are validated with Thunderbolt 3 support. It really does get interesting in the high-end battle as to which features matter the most and who executes the best.

For aesthetics, the M8E moves away from the garish red and black, using a modern grey/black combination using red accents. The use of a rear-IO/audio guard stretching around the motherboard and over the power delivery certainly gives it a feel of bulk, along with the full-length PCIe slots, a U.2 port, and extra ASUS specific hardware features. There’s an RGB LED in the large chipset heatsink for the ROG logo, allowing for some customization.

For performance, we take it in two chunks. For CPU/GPU performance, the use of MultiCore Turbo by default puts the M8E in line with other MCT enabled motherboards. However on the system performance metrics, the M8E breaks some records. DPC Latency sits at 20 microseconds, and is our new record holder (the Maximus VIII Impact had that honor up until now, with 49 microseconds). The audio dynamic range is also top of the charts, and our stripped POST times are top three. Power consumption is mid-range, as is USB performance. But those new DPC and SNR records are hard to ignore, typically coming from optimized firmware, hardware and trace routing.

ASUS also still holds a number of cards on the BIOS/Software front, using features like Sonic Stage, a new version of GameFirst IV to allow multi-gate teaming (aka sending data down specific pipes), Keybot, RAMDisk, Sonic Radar, a new PC Cleaner we saw with the Impact, and SSD Secure Erase. AI Suite still remains the centerpiece for Windows software. There is still room for improvement here, especially with the update software.

There are a lot of positive things about the Maximus VIII Extreme, and the typical idioms that surround a $500 motherboard still apply: if a user is in this market, will they use all the features it has to offer? ASUS talks more about its active feature-set (features you interact with) more than the passive features (power delivery, DRAM T-Topology) which are part of the underlying design, because users buy on features. ASUS has argued that the Extreme is for the extreme users who do want everything, and that extra few percentage points of performance. Through our testing, it certainly earns top spot in some important benchmarks.

Quick Links to Other Pages

Board Features, In The Box
Visual Inspection and Test Setup
BIOS
Software
System Performance (Audio, USB, Power, POST Times on Windows 7, Latency)
CPU Performance, Short Form (Office Tests and Transcoding)
Gaming Performance 2015 (R7 240, GTX 770, GTX 980)
Conclusions

Quick Board Feature Comparison

Motherboard Comparison
	ASUS Maximus VIII Extreme	ASRock Z170 Extreme7+ASUS Maximus VIII ImpactASUS Z170-AGIGABYTE Z170X-Gaming G1GIGABYTE Z170X-UD5 THMSI Z170 Gaming M7Supermicro C7H170-MASUS Maximus VIII Extreme
Socket	LGA1151	LGA1151
MSRP at Review	$500	$230
DRAM	4 x DDR4	4 x DDR4
PCIe Layout	x8/x4/x4	x8/x8
BIOS Version Tested	1101	142
MCT Enabled Automatically?	Yes	Yes
USB 3.1 (10 Gbps)	ASMedia ASM1142 2xA Intel Alpine Ridge A+C	ASMedia ASM1142 1 x Type-A 1 x Type-C
M.2 Slots	1 x PCIe 3.0 x4	2 x PCIe 3.0 x4
U.2 Ports	1 x PCIe 3.0 x4	No
Network Controller	1 x Intel 219-V 1 x 3T3R 802.11ac	1 x Killer E2400
Audio Controller	Realtek ALC1150 with ESS ES9023P DAC bypass	Realtek ALC1150
HDMI 2.0	No	No

ASUS Maximus VIII Extreme Overclocking

Experience with ASUS Maximus VIII Extreme

For our M8E overclocking under BIOS 1101, there are two levels defined by the TPU as well as a Gamers’ OC option in the BIOS. All three of these worked, and gave a good indication of where our manual overclocks should go. One of the main advertised features of the Extreme is going to be the overclockability, especially for extreme users wanting to push memory and processor frequency under liquid nitrogen. ASUS employs several well respected extreme overclockers and former world record holders as part of their ROG design team, allowing designs to be iterated over for better performance. While we don’t test with liquid nitrogen for reviews, our main indication here is trying to get a higher frequency for less voltage, temperature or power.

Methodology

Our standard overclocking methodology is as follows. We select the automatic overclock options and test for stability with PovRay and OCCT to simulate high-end workloads. These stability tests aim to catch any immediate causes for memory or CPU errors.

For manual overclocks, based on the information gathered from previous testing, starts off at a nominal voltage and CPU multiplier, and the multiplier is increased until the stability tests are failed. The CPU voltage is increased gradually until the stability tests are passed, and the process repeated until the motherboard reduces the multiplier automatically (due to safety protocol) or the CPU temperature reaches a stupidly high level (100ºC+). Our test bed is not in a case, which should push overclocks higher with fresher (cooler) air.

Overclock Results

Both the TPU L1 and Gamer’s OC presets gave a CPU multiplier staggered based on CPU loading, with the latter pushing up to 4.8 GHz on a single thread meaning a high voltage was needed. Interestingly TPU L1 actually decreases performance in our POV-Ray benchmark due to four-core loading being set to 4.1 GHz, whereas at stock settings the CPU implements multi-core turbo, giving 4.2 GHz on all cores. This makes our TPU L1 test more of a declock for fully-threaded workloads.

In our manual overclocks, the Level 7 load line calibration pushed the load voltage above our setting, meaning that the 4.8 GHz stable frequency was sitting at a toasty 1.536 volts. OCCT’s reading software was not much help for quantitative temperature readings, but qualitatively it shows that setting your own voltage for even 4.3 GHz pushes the temperature down from stock frequencies (4.2 GHz).

Compared to the Z170X-Gaming G1, technically the ASUS board hit 4.8 GHz when the GB motherboard only hit 4.7 GHz on the same processor, but this is mainly down to voltage: even at a high LLC, the other motherboard was not applying the full voltage (1.396 volts for 4.7 GHz despite the 1.425 volts setting). At 1.5 volts we were seeing very high temperatures (90C+), meaning that more extreme cooling would be needed to go further. But the M8E applies LLC more aggressively in comparison of the two.

Board Features

Having gone through and generated the following table for the M8E, I find it mildly amusing, especially as I’ve just put a $120 motherboard on the test bed here. By comparison, instead of most of the sections saying none/blank, when dealing with a $500 motherboard everything is filled up. More SATA ports, more features and more room to add things means that a halo motherboard has to be the Rambo of a PC build.

ASUS Maximus VIII Extreme
Warranty Period	3 Years
Product Page	Link
Price	Amazon US
Size	E-ATX
CPU Interface	LGA1151
Chipset	Intel Z170
Memory Slots (DDR4)	Four DDR4 Supporting 64GB Dual Channel Up to 3866 MHz
Memory Slots (DDR3L)	None
Video Outputs	HDMI to 4096x2160 @ 24 Hz DisplayPort at 4096x2304 @ 60 Hz
Network Connectivity	Intel I219-V 3T3R 802.11ac Wi-Fi Go! Module
Onboard Audio	Realtek ALC1150 with ESS ES9023P DAC bypass
PCIe Slots for Graphics (from CPU)	3 x PCIe 3.0 (x16, x8/x8, x8/x4/x4)
PCIe Slots for Other (from PCH)	1 x PCIe 3.0 x4 2 x PCIe 3.0 x1
Onboard SATA	Six, RAID 0/1/5/10 Two from ASMedia ASM1061
Onboard SATA Express	Two, RAID
Onboard M.2	1 x PCIe 3.0 x4 or SATA, RAID 0/1, NVMe
Onboard U.2	1 x PCIe 3.0 x4 (switched with M.2)
Thunderbolt	TB3 via Type-C
USB 3.1	2 x Type-A from ASMedia ASM1142 Controller 1 x Type-A and 1 x Type-C from Intel Alpine Ridge
USB 3.0	4 x Rear Panel 4 via headers
USB 2.0	6 via headers
Power Connectors	1 x 24-pin ATX 1 x 8-pin CPU 1 x 4-pin CPU
Fan Headers	1 x CPU (4-pin) 1 x CPU_OPT (4-pin) 4 x CHA/SYS (4-pin)
IO Panel	1 x Combination PS/2 4 x USB 3.0 3 x USB 3.1 Type-A 1 x USB 3.1 Type-C 1 x Network RJ-45 (Intel I219-V) HDMI DisplayPort Clear CMOS Button USB BIOS Flashback Button 3T3R 802.11ac Wi-Fi Go! Module Audio Jacks
Other Features	OC Panel Header Thunderbolt Header 4-pin EZ-PLUG Header Front Panel Header 5-pin Fan Extension Header MemOK! Button Slow Mode Switch 9 x Voltage measurement points 3 x Thermal Sensor Headers 1 x DRAM Channel Jumper Power/Reset Buttons BIOS Switch Button SLI/CFX Switch LN2 Mode Jumper Safe Boot Button ReTry Button

The big active features for ASUS come in at the 3T3R tri-stream WiFi, an ESS DAC, Thunderbolt 3 support via Intel’s Alpine Ridge controller, a total of four USB 3.1 ports split between the Alpine Ridge and ASMedia’s ASM1142 controller and then the sheer amount of switches and buttons onboard for power users to configure their experience. The OC Panel header for both power users and extreme overclockers comes in handy with the bundled OC Panel.

Using the chipset diagram, it shows a slightly more complex picture. Everything on the left side is what we would expect, including the complex way that x8/x4/x4 is implemented on the PCIe side, although it is worth noting that the HDMI 1.4b port is provided through the Alpine Ridge controller rather than the CPU. I would assume this is actually just a bypass to help with routing though it may suggest that the TB3 controller cannot use HDMI when the DisplayPort functionality is in use. I’ll be synchronizing with ASUS on this.

On the right hand side we see that two of the SATA ports (4/5) share bandwidth with the PCIe x4 slot at the bottom of the board. When SATA devices are connected, the PCIe slot will reduce to x2 bandwidth. Also on the right hand side is an ASM1187 controller, which looks like a 6-port PCIe switch. Taking one PCIe lane in, it gives an output to five ports which include the two ASMedia SATA ports, two of the rear USB 3.0 ports, the Wi-Fi module and the two PCIe x1 slots. However, unless one of the PCIe x1 slots is using full bandwidth, I doubt it is much of an issue, and if anything it would be a latency issue. But it might also explain why we could not get proper USB 3.0 speed results through the ASMedia controller.

In The Box

We get the following:

User Manual
Driver DVD
Rear IO Shield
OC Panel plus 5.25-inch Bay
Fan Extension Board
Wi-Fi Antenna
Thermal Probes
CPU Installation tool
Eight SATA Cables
Q-Connectors
ASUS ROG Stickers
ASUS ROG Door Handle Sign
Flexi-CrossFire Connector
Flexi-SLI Connector

At $500 and being part of the ROG brand it means the in-box goodies should be plentiful. The star of the pack is the OC Panel, used by extreme overclockers to make adjustments on the fly or system builders to monitor fan speeds/temperatures with one-button overclocks.

We’ve discussed the OC Panel at length before, and this is the third generation with the same model, featuring more fan headers, VGA Hotplug and extra switches for system control.

Also in the box are a set of thermal probes to use on the extra thermal probe headers on the motherboard, giving the ASUS software extra read points for temperature if the user wants to monitor specific zones in their build. The CPU installation tool is there to help new build users put the processor in the motherboard, although I didn’t find much use for it (I’ve never dropped a CPU in a socket yet…). It is interesting to see so many SATA cables in the box though, however these are mostly likely bought in bulk and minimal cost to a board like this.

ASUS also sells the Maximus VIII Extreme/Assembly, which comes with a custom audio output dock as well as a Tahuti Networks based 10 gigabit Ethernet card using RJ-45.

Visual Inspection

As mentioned on the first page in the overview, ASUS is moving the Extreme line into something a little more reserved and subtle, but still with a feeling of bulk and utility. We saw this with the Rampage IV Black Edition, although the full black look is at the other end of the scale. The M8E comes in more refined, using a consistent black and grey coloring across the heatsinks, DRAM slots, PCIe slots, SATA ports and USB 3.0 headers to make sure everything looks in place. Grey can be boring however, so the look has red highlights and accents on the heatsinks using the angular motif and design ASUS has liked to use in the past couple of years. While the ‘Maximus VIII’ and ‘Extreme’ name is recessed into the grey heatsink, the ‘SupremeFX’ name is raised in red, with the ROG logo on the chipset heatsink recessed but hiding an RGB LED underneath. Using the software, users can make this logo pulse a number of colors for looks, or turn it off to create a stealth-like system.

The power delivery heatsinks around the socket cover three sides and encompass the rear I/O cover as well. This cover extends down to the audio segment of the motherboard, purely because the rear I/O and audio can be two of the biggest culprits for disturbing aesthetics. It should be noted that the heatsink below the socket is in the area normally reserved for a PLX8747 chip which would enable 3-way and 4-way SLI by multiplexing the PCIe lanes. The fact that all the PCIe 3.0 slots are full-length might suggest that a PLX chip is present, as this is a common connection. However, there is no PLX chip here. The first three PCIe slots use sixteen lanes from the CPU and operate in x16, x8/-/x8 or x8/x4/x4 modes while the last slot is an x4 implementation from the chipset. For SLI, due to NVIDIA’s restrictions, eight PCIe lanes are needed at a minimum. This means we are limited to 2-way SLI here.

Of the six fan headers onboard, the socket area has quick access to four of them – two 4-pin CPU headers and a 4-pin chassis header in the top right and a 4-pin chassis header just above the first PCIe slot. The final two headers are at the bottom of the motherboard, both 4-pin.

The power delivery, by virtue of being a motherboard that ASUS expects extreme users to overclock using liquid nitrogen on, is hyper-engineered as a result.

The thirteen phases here are most likely in a 12+1 configuration, with the 12 being multiplexed as 2x6 or 3x4. Where ASUS’ main competitor uses International Rectifier chokes and PWMs, ASUS combines MicroFine alloy chokes (provides a predictable voltage response) with Infineon OptiMOS MOSFETs for a higher current drain and dual PWM controllers for finer CPU and CPU graphics voltage adjustments. There’s also 10K black capacitors there, rated for 10000 days compared to 2000 on regular motherboards, but at this price most motherboards will have 5k/8k/10k/12k implementations depending on the motherboard manufacturer.

On the top right of the motherboard are the DRAM slots and a number of the enthusiast options. The start/reset buttons are standard on most motherboards above $150, as is the two-digit debug display. Below the reset button is a set of DIP switches for PCIe slots, allowing enthusiasts to disable certain PCIe slots if needed (usually to remove potential erratic behavior in sub-zero mode, or if GPUs can’t be removed but an overclocking run on a single GPU is needed). Below this is a pair of jumpers, used for enabling/disabling specific memory channels.

Next to this is an LN2 mode jumper, which when enabled will give more BIOS options related to liquid nitrogen overclocking as well as provide certain setting safeguards. Below this is a slow mode switch, forcing the processor into a low-frequency state (typically 800 MHz) which guarantees booting into an operating system. Typically extreme overclockers will use this in two ways – either to debug a bad overclock, or to implement an extreme overclock for a short time/short benchmark before taking a score before going back to slow mode to ensure the system is stable enough to take a screenshot of their benchmark score for overclocking leagues.

The nine silver dots below this are the onboard voltage read points. Overclockers use these with their multimeters to read the voltage of certain parts of the system (core, graphics, DRAM, chipset, system agent) which might not be read correctly by software. As some overclockers will be adjusting frequency and voltage on the fly, this is a way of detecting that the voltage required is set properly. Next to these are a set of three buttons, linked to ASUS’ ReTry, Safe_Boot and Mem_OK features for recovering an unstable system.

A note on the DRAM slots – they are single side latched, meaning that users should be aware if their memory is firmly inserted on both sides (the upside of this is making it easier to remove memory when a full-length large GPU is being used which blocks the bottom latches if present).

Moving down the right-hand side of the board there are two USB 3.0 headers, one at right angles, for built-in case ports. Below this are the SATA ports, combined with two SATA Express ports, then a U.2 port. The SATA ports in black come from an ASMedia controller, whereas the rest are provided by the chipset. If we ignore SATA Express (because everyone should at this point), the important thing here is U.2. As a new (new-ish) standard for storage offering PCIe 3.0 x4 bandwidth, I have a strong feeling that motherboards will slowly migrate this way depending on chipset bandwidth. As shown in the image above, it takes the place of two SATA ports for one U.2 drive, and comes in at the same height. We are in an age where motherboards easily come with six or more SATA ports, most of which remain unused, while a U.2 drive (2.5-inch or 3.5-inch) could run into the terabytes for storage under a single cable. U.2 is ultimately competing with M.2, but we are waiting for the main SSD companies to release their U.2 devices which can offer more storage and better cooling characteristics in exchange for volume and PC location. Intel already released the SSD 750 (which is one more released drive over SATA Express which has zero), we are just waiting on others. U.2, on the whole, is more of an enterprise play. The cables are more expensive than SATA (~$1 vs $0.02 in bulk), which increases the cost, but I find that a minor argument if we can get high-speed multi-TB storage. It is worth noting at this time that Intel does not have a PCIe SSD controller smaller than 22mm, so if 3D XPoint ever comes to consumers, either Intel needs a new PCIe controller for M.2 or it will be U.2 only until then.

On the audio side, ASUS hides most of it under the SupremeFX shield, but underneath holds an enhanced Realtek ALC1150 implementation using an ESS ES9023P DAC via a bypass. The solution also includes enhanced filter caps, a headphone amplifier and a sense amp to allow for 32-600 ohm headphones. There is also PCB separation of the digital/analog sections of the motherboard and gold-plated audio connectors.

On the rear panel we an interesting display – zero USB 2.0 ports. Instead we have one of the few motherboards with more than two USB 3.1 ports, here showing two Type-A ports in red on the left from an ASMedia ASM1142 controller and then a Type-A and Type-C from Intel’s Alpine Ridge controller. That Type-C port is also qualified for Thunderbolt 3 support up to 40 Gbps using an active cable. The blue ports are USB 3.0 ports from the chipset, and we also get an Intel I219-V network port and a PS/2 combination port. On the far left are two buttons with the top one resetting the BIOS and the bottom one allowing for ASUS’ USB BIOS Flashback which can flash a BIOS without a CPU, DRAM or GPU present.  Elsewhere on the rear panel is the 3T3R Wi-Fi Go module, a Displayport/HDMI port for onboard graphics, and the audio jacks.

Test Setup

Test Setup
Processor	Intel Core i7-6700K (ES, Retail Stepping), 91W, $350 4 Cores, 8 Threads, 4.0 GHz (4.2 GHz Turbo)
Motherboards	ASUS Maximus VIII Impact
Cooling	Cooler Master Nepton 140XL
Power Supply	OCZ 1250W Gold ZX Series Corsair AX1200i Platinum PSU
Memory	Corsair DDR4-2133 C15 2x8 GB 1.2V or G.Skill Ripjaws 4 DDR4-2133 C15 2x8 GB 1.2V
Memory Settings	JEDEC @ 2133
Video Cards	ASUS GTX 980 Strix 4GB MSI GTX 770 Lightning 2GB (1150/1202 Boost) ASUS R7 240 2GB
Hard Drive	Crucial MX200 1TB
Optical Drive	LG GH22NS50
Case	Open Test Bed
Operating System	Windows 7 64-bit SP1

Readers of our motherboard review section will have noted the trend in modern motherboards to implement a form of MultiCore Enhancement / Acceleration / Turbo (read our report here) on their motherboards. This does several things, including better benchmark results at stock settings (not entirely needed if overclocking is an end-user goal) at the expense of heat and temperature. It also gives in essence an automatic overclock which may be against what the user wants. Our testing methodology is ‘out-of-the-box’, with the latest public BIOS installed and XMP enabled, and thus subject to the whims of this feature. It is ultimately up to the motherboard manufacturer to take this risk – and manufacturers taking risks in the setup is something they do on every product (think C-state settings, USB priority, DPC Latency / monitoring priority, overriding memory sub-timings at JEDEC). Processor speed change is part of that risk, and ultimately if no overclocking is planned, some motherboards will affect how fast that shiny new processor goes and can be an important factor in the system build.

For reference, the ASUS Maximus VIII Extreme, on our testing BIOS 1101, MCT was enabled by default. Also, the FCLK 10x ratio was present in the BIOS tested at the time of testing.

Many thanks to...

We must thank the following companies for kindly providing hardware for our test bed:

Thank you to AMD for providing us with the R9 290X 4GB GPUs.
Thank you to ASUS for providing us with GTX 980 Strix GPUs.
Thank you to ASRock and ASUS for providing us with some IO testing kit.
Thank you to Cooler Master for providing us with Nepton 140XL CLCs.
Thank you to Corsair for providing us with an AX1200i PSU.
Thank you to Crucial for providing us with MX200 SSDs.
Thank you to G.Skill and Corsair for providing us with memory.
Thank you to MSI for providing us with the GTX 770 Lightning GPUs.
Thank you to OCZ for providing us with PSUs.
Thank you to Rosewill for providing us with PSUs and RK-9100 keyboards.

ASUS Maximus VIII Extreme BIOS

A large portion of this page will be identical to the Maximus VIII Impact review, updated for specific M8E features.

For users well accustomed to BIOS layout, it makes sense when a company uses the same basic libraries throughout their product stack. It makes sense for time and development, and there can be some leeway in customization for different types of products. So this is what I mean when I say that users who are familiar with ASUS’ main line of motherboards (the -Pro, the -A, the –Deluxe and other) will also understand what goes on with ROG. There are differences, and the first two to notice are the color scheme moving red but also that the BIOS enters straight into advanced mode, bypassing EZ mode.

But let us step back a bit, and move to EZ mode. For users who want to deal only in EZ mode, there is a setting which forces it as the default BIOS entry point.

Similar to other EZ modes we have seen from ASUS, this one gives details on the motherboard name, the BIOS version, the CPU installed, the speed of the CPU, the amount of memory installed, a graph of CPU temperature over time (useful if you’ve forgot to plug in the CPU fan… oops), the CPU voltage, the motherboard chipset temperature the speed the memory is running at, a per-DRAM slot label of what memory is installed, a per-SATA port label of what drives are installed, a quick button for XMP, a quick button for RST, a per-fan rundown of fan speeds, a diagram of the fan power control for the CPU fan, a quick button to customize the fan profiles, an EZ system tuning list for quick updating, and a boot priority list. Pretty much 90% of what you want a motherboard for, especially if you are the family computer guy fixing it.

Pressing F11 brings up the EZ Tuning Wizard to help users get some basic overclocking and RAID controls.

The EZ Wizard asks a couple of questions, such as what the system is used for (gaming or daily tasks/media consumption), what cooling is installed (stock cooler, tower cooler, liquid cooling, unknown), and then uses a lookup table and attempts to apply a sufficient overclock. It beats many ‘set it and see’ overclocking tools on other motherboards purely on user experience, even if results are similar.

Here for example I chose Daily Computing with a Stock Cooler, and it offered a 12% overclock for the i7-6700K (moving from 4.0 GHz to 4.5 GHz) and no change in the DRAM (DDR4-2133), then asked to enable it.

For the EZ RAID option, this makes the task of implementing RST on Intel configured RAID ports easier by providing a step-by-step guide.

Also on the EZ Mode page we have access to quick fan controls under Q-Fan:

The system will allow each fan to be configured either by PWM or DC controls where possible, and offers four presets (standard, silent, turbo, full speed) as well as manual control of a multi-point fan gradient. On the left hand side is the ‘Optimize All’ option, which provides per-fan tuning.

Moving back into Advanced Mode, and similar to previous motherboards ASUS is offering a My Favorites menu to allow users who have specific settings they want to tweak (typically overclockers), then options can be added here. For the Z170 platform, ASUS is now pre-filling the My Favorites menu with a number of options they feel are best suited for overclocking, such as core ratios, base frequency, DRAM multiplier, voltages and power options.

For the main glut of overclocking options though, the Extreme Tweaker menu has them all.

A wider range of CPU overclocking options are exposed on this first set of screens, with additional menu options for DRAM, power management and ‘extreme tweaking’. For users with the LN2 header enabled, more obscure options are also offered. However, the first option at the top is relatively interesting as a set of overclocking presets:

The majority of these are for extreme overclockers, but the Gamers’ OC profile is one we have tested in the OC section (along with the TPU options). The Gamers’ OC gives a 48/47/46/45 multiplier overclock with 1.425 volts set in the BIOS with LLC at Level 7. On our test bed with our #2 CPU, this passed our tests.

Similarly in the DRAM section, we also get a list of presets for extreme overclocking:

Most of these require knowledge into the memory you have, and are typically used by those close to ASUS’ in-house overclocking team.

Moving away from overclocking, and the Advanced menu holds most of the typical motherboard options for enabling/disabling controllers, organizing storage controls, C-states and USB configuration. I think the best bit about this is the SMART information screen.

Similar to OS tools to read SMART data, here we get information about power-on hours, power cycles and drive temperature. This sort of information tool is slowly moving into BIOSes of all the manufacturers, which is a good thing to see.

A menu for the Thunderbolt controller is also here, including Boot and Wake support.

Next up in the BIOS is the monitoring tools, which also doubles as the place for manual fan controls without the graph.

As the Impact has several additional temperature sensor headers onboard for additional thermistors, these can be added and configures here as well.

The Q-Fan control in text looks similar to other fan control software, and allows for separate fan header adjustment in DC or PWM mode.

Boot override and CSM controls are found in the Boot Menu, which also has the option for Above 4G Decoding if anyone wants to pair the motherboard with a MIC.

The last set of features for the BIOS are in the Tool menu.

ASUS has updated its EZ Flash tool to generation 3, allowing it to also probe an online server for an updated BIOS version, which is similar to what ASRock does. Secure Erase still features in the ROG BIOSes, as well as overclocking profiles, SPD information and GPU information. The thing missing from ASUS’ repertoire is a Board Explorer mode, similar to what ASRock and MSI have, which shows a diagram of the motherboard and what is installed in each port. As a method of showing if certain DRAM modules are not detected, or SATA drives not found, it provides a good user experience for most users (though one could argue that the various lists around the BIOS already do this, though they are not currently in one place).

 

ASUS Maximus VIII Extreme Software

A large portion of this page will be identical to the Maximus VIII Impact review, updated for specific M8E features.

The software tools from ASUS, similar to the BIOS, come in two flavors. A base blue contains the majority of features that a wide portion of users might decide suits their needs, but the ROG platform adds in a few specific extras (some of which are externally licensed with an ROG theme). The main interface is still AI Suite featuring ‘Dual Intelligent Processors 5’, with a few more satellite software programs to complement the standard functionality.

First up is Boot Setting, a small app I use quite a lot for one main reason - the DirectBIOS button. For any users taking advantage of AHCI fast booting, this button is to instantly reset the machine and reboot into the BIOS to make changes. As a hardware reviewer, I tend to fiddle with the BIOS a fair bit, especially when overclock testing, to a tool like this is great. That being said, once a system is up and running, it rarely gets used again.

New on the scene for ROG is RAMCache, which is different to RAMDisk (see below). The RAMCache tool is similar to the tools we’ve seen on certain brands of SSD software – earmark up to a quarter of the DRAM to act as a fast storage cache which then flushes out to the SSD in a non-time critical manner. In theory, great – it worked fine in our little test scenario, although the benefits over a regular SSD are minimal. The downside is write commits if the system fails. If you have data in the cache and power is lost, or the system dumps garbage at you requiring a hard reset, the data in the cache may be lost - such as that save game you have been working on. The best way for ASUS to expand this is to offer more options – how long data should reside in the cache before being write committed to the drive, or for certain programs/files to bypass the cache completely and write immediately.

RAMDisk is the other side of the equation, especially if you have more RAM than you can shake a stick at (don’t start shaking sticks at sheep, I’m not to be held liable for injuries obtained). Here we can allocate a portion of the memory available as a drive to use when the machine is in action. This is handy in some scenarios, such as migrating a non-critical virtual machine or batching media to be processed. Similarly with the RAMDisk, data is lost if the machine loses power.

As part of the SupremeFX audio package, we also get Sonic Studio software, which acts as a ‘smart EQ’ for gaming that can focus on certain sounds for audio output. Similar to MSI’s Nahimic, this is a glorified EQ adjuster, although without the song and dance (or licensing fees) and it still allows you to have manual EQ settings if you want.

There are settings for different game types, as well as a microphone input/output adjuster and tools to help with audio when streaming.

As part of the ROG package, ASUS also licenses CPU-Z with a custom skin. This is a tool used by overclockers to verify what processor is being used in a system, as well as the speed, the memory, and other functionality. By using an ROG skin, the idea is that when overclocking world records are made and promoted using the ROG skinned CPU-Z, there’s a subtle mental link in there between the brand and the performance.

Keybot is ASUS’ in-house macro tool to allow gamers to predefine a series of keyboard commands (with appropriate delays) to enhance their gaming performance and/or experience. The tool can also be used to map certain programs to keys, or other things such as volume/playback.

As a macro tool, it falls under the simplistic heading, only because making a full-on macro tool such as AutoHotKey requires a team and a million more options/commands besides.

Keybot offers a hardware saved ‘Smart Input’ script that can be called regardless of the OS or setting of the hardware. This can be interesting for users who want a quick string of characters that can be applied anywhere, although it is worth noting that the text is not stored encrypted, so ASUS recommends against using it for passwords.

For memory sub-timing adjustments, the MemTweakIt tool from previous ROG generations is updated for Skylake and also included in the software suite.

For networking, ASUS offers the ROG line with GameFirst III, an in-house custom networking tool for prioritization. This tool allows users to promote which data streams (such as gaming and VOIP) over others (such as windows updates or downloads) and maintain latency when multiple things are happening at once – at the expense of some CPU overhead and power. ASUS does this with the Intel networking, which provides some control similar to cFos seen on other motherboards, but arguably less control than something like Killer which also uses hardware controls to accelerate some features. Pretty much every networking software program has issues with user experience too, with little optimization in terms of style or handling except for those dedicated to network prioritization. There’s also the extra problem if someone else on the network is chewing up the data, which cannot be solved by simple motherboard software.

GameFirst III is currently being updated to GameFirst IV, which should be out of beta soon if it isn’t already. GameFirst IV allows for ‘multi-gate teaming’, which is a marketing label applied to software that allows the user to define which network connection certain data should go down. This is similar to Rivet Network’s Killer implementation called DoubleShot-X3 Pro: you can direct critical (game / VOIP) traffic through the fastest network connection, then downloads/non-critical updates down a slower connection (Wi-Fi, LTE). While this is called teaming in marketing speak, teaming in a technical sense would make two connections appear as one, splitting and recombining data packets at each end from a single operation, doubling potential bandwidth. This does not do this, using multiple software requests for network access to prioritize throughput instead.

AI Suite 3

Finally we move on to AI Suite 3, which for the most part contains the software tools we’ve written about many times before. The front page is part of ASUS’ Dual Intelligent Processor program, version five. The two intelligent processors are the TPU (Turbo Processing Unit) and the EPU (Energy Processing Unit) which are separate ICs on board to help control both overclocking and power use. These two options are mixed with three other modes (Fan Xpert 3, DIGI+ Power, and Turbo App) for the five apps listed above.

The TPU menu offers the usual array of voltages and per-core overclocking. In generations past we saw graphs showing how the voltage responded to load and could adjust the load-line calibration to compensate, but unfortunately this seems to have regressed here.

The Fan Expert tools are similar to those we saw in the BIOS under Q-Fan, with the fan tuning mode also present. One difference in the software here is the result screen when the tuning is finished:

Here is the result of my CPU fan, showing a dead zone below 20% power and a non-linear response in the controllable range. This shows the disparity between fan speed and applied fan power which still needs to be addressed across the motherboard industry.

Also from the AI3 front page are the DIGI+ Power controls, giving options to extend power phase limits, response times, load line calibration and temperature limits. Most of these are usually untouched by the majority of users, but are given for those who might have an odd piece of silicon in the socket that behaves a little differently.

The EPU option is a way for the system to configure different power modes, with the idea of saving energy by running in a more efficient state when latency is not a factor. In this case, when the user is idle, the EPU will attempt to limit the CPU power to 25W and reduce the voltage/fan profiles to do so.

The last stage is Turbo App, which allows the user to configure certain overclocks or LAN prioritization modes to various applications and then rank them in a priority list.

New to the ASUS software package is a temporary file remover called Free Space. With a preset list of directories that typically harbor temporary files or caches, the system will look through the ones selected and let the user know how much space can be saved. The software can then delete these files to save space. This is similar to freeware software I already use on most of my rigs called CCleaner, which has been in the industry for many years and works quite well, as it also probes the registry, offers a mass uninstall feature, and also has a data security overwrite mode (overwrite a drive seven times to ensure data is destroyed). I’d suggest motherboard manufacturers organize a licensing deal with CCleaner if they really want to pursue this line of software.

Other software in AI Suite we have covered in previous reviews:

USB Boost: For suitable devices, implements a newer USB protocol to improve USB 3.0 and USB 3.1 speed.
System Information: Breakdown of the hardware specifications for motherboard, CPU and DRAM.
USB BIOS Flashback: Prepare a USB with a BIOS for updating, or save the current BIOS.
Lighting Control: Used to make adjustments to the RGB lighting.

System Performance

Not all motherboards are created equal. On the face of it, they should all perform the same and differ only in the functionality they provide - however this is not the case. The obvious pointers are power consumption, but also the ability for the manufacturer to optimize USB speed, audio quality (based on audio codec), POST time and latency. This can come down to manufacturing process and prowess, so these are tested.

Power Consumption

Power consumption was tested on the system while in a single MSI GTX 770 Lightning GPU configuration with a wall meter connected to the OCZ 1250W power supply. This power supply is Gold rated, and as I am in the UK on a 230-240 V supply, leads to ~75% efficiency > 50W, and 90%+ efficiency at 250W, suitable for both idle and multi-GPU loading. This method of power reading allows us to compare the power management of the UEFI and the board to supply components with power under load, and includes typical PSU losses due to efficiency. These are the real world values that consumers may expect from a typical system (minus the monitor) using this motherboard.

While this method for power measurement may not be ideal, and you feel these numbers are not representative due to the high wattage power supply being used (we use the same PSU to remain consistent over a series of reviews, and the fact that some boards on our test bed get tested with three or four high powered GPUs), the important point to take away is the relationship between the numbers. These boards are all under the same conditions, and thus the differences between them should be easy to spot.

By the nature of being a large E-ATX motherboard with a number of extra controllers, one would expect the M8E to draw a fair bit of power, even under CPU load.

Non UEFI POST Time

Different motherboards have different POST sequences before an operating system is initialized. A lot of this is dependent on the board itself, and POST boot time is determined by the controllers on board (and the sequence of how those extras are organized). As part of our testing, we look at the POST Boot Time using a stopwatch. This is the time from pressing the ON button on the computer to when Windows 7 starts loading. (We discount Windows loading as it is highly variable given Windows specific features.) 

Perhaps due to the emergence of Windows 10 and fast boot sequences, fewer motherboard companies are worrying about POST times, although they are now arguably the longest part of a start-up process, especially with the additional DDR4 training needed for validation. The Extreme is reasonably comfortable for its size at 16.50 seconds.

Rightmark Audio Analyzer 6.2.5

Rightmark:AA indicates how well the sound system is built and isolated from electrical interference (either internally or externally). For this test we connect the Line Out to the Line In using a short six inch 3.5mm to 3.5mm high-quality jack, turn the OS speaker volume to 100%, and run the Rightmark default test suite at 192 kHz, 24-bit. The OS is tuned to 192 kHz/24-bit input and output, and the Line-In volume is adjusted until we have the best RMAA value in the mini-pretest. We look specifically at the Dynamic Range of the audio codec used on board, as well as the Total Harmonic Distortion + Noise.

Audio performance from the Extreme gives it the highest SNR of any 100-series motherboard we’ve tested before.

USB Backup

For this benchmark, we transfer a set size of files from the SSD to the USB drive using DiskBench, which monitors the time taken to transfer. The files transferred are a 1.52 GB set of 2867 files across 320 folders – 95% of these files are small typical website files, and the rest (90% of the size) are small 30 second HD videos. In an update to pre-Z87 testing, we also run MaxCPU to load up one of the threads during the test which improves general performance up to 15% by causing all the internal pathways to run at full speed.

Due to the introduction of USB 3.1, as of June 2015 we are adjusting our test to use a dual mSATA USB 3.1 Type-C device which should be capable of saturating both USB 3.0 and USB 3.1 connections. We still use the same data set as before, but now use the new device. Results are shown as seconds taken to complete the data transfer.

With ASUS’ USB Turbo, we get great performance in our USB 3.0 test. Unfortunately due to the nature of the Intel USB 3.1 controller, our testing software reports erroneous results stating that a transfer is complete faster than could be possible (and it’s a highly variable result). Interestingly we also had problems with the ASMedia controller, which behaved similarly.

DPC Latency

Deferred Procedure Call latency is a way in which Windows handles interrupt servicing. In order to wait for a processor to acknowledge the request, the system will queue all interrupt requests by priority. Critical interrupts will be handled as soon as possible, whereas lesser priority requests such as audio will be further down the line. If the audio device requires data, it will have to wait until the request is processed before the buffer is filled.

If the device drivers of higher priority components in a system are poorly implemented, this can cause delays in request scheduling and process time.  This can lead to an empty audio buffer and characteristic audible pauses, pops and clicks. The DPC latency checker measures how much time is taken processing DPCs from driver invocation. The lower the value will result in better audio transfer at smaller buffer sizes. Results are measured in microseconds.

For better or worse, DPC Latency has been a wild ride on Z170. Some companies care deeply, others are not too fussed. Despite this, ASUS seems to have nailed down the formula for a great DPC Latency, and the Maximus VIII Extreme takes the crown from its smaller sibling in style.

CPU Performance, Short Form

For our motherboard reviews, we use our short form testing method. These tests usually focus on if a motherboard is using MultiCore Turbo (the feature used to have maximum turbo on at all times, giving a frequency advantage), or if there are slight gains to be had from tweaking the firmware. We leave the BIOS settings at default and memory at JEDEC (DDR4-2133 C15) for these tests, making it very easy to see which motherboards have MCT enabled by default.

Video Conversion – Handbrake v0.9.9: link

Handbrake is a media conversion tool that was initially designed to help DVD ISOs and Video CDs into more common video formats. For HandBrake, we take two videos (a 2h20 640x266 DVD rip and a 10min double UHD 3840x4320 animation short) and convert them to x264 format in an MP4 container.  Results are given in terms of the frames per second processed, and HandBrake uses as many threads as possible.

Compression – WinRAR 5.0.1: link

Our WinRAR test from 2013 is updated to the latest version of WinRAR at the start of 2014. We compress a set of 2867 files across 320 folders totaling 1.52 GB in size – 95% of these files are small typical website files, and the rest (90% of the size) are small 30 second 720p videos.

Point Calculations – 3D Movement Algorithm Test: link

3DPM is a self-penned benchmark, taking basic 3D movement algorithms used in Brownian Motion simulations and testing them for speed. High floating point performance, MHz and IPC wins in the single thread version, whereas the multithread version has to handle the threads and loves more cores. For a brief explanation of the platform agnostic coding behind this benchmark, see my forum post here.

Rendering – POV-Ray 3.7: link

The Persistence of Vision Ray Tracer, or POV-Ray, is a freeware package for as the name suggests, ray tracing. It is a pure renderer, rather than modeling software, but the latest beta version contains a handy benchmark for stressing all processing threads on a platform. We have been using this test in motherboard reviews to test memory stability at various CPU speeds to good effect – if it passes the test, the IMC in the CPU is stable for a given CPU speed. As a CPU test, it runs for approximately 2-3 minutes on high end platforms.

Synthetic – 7-Zip 9.2: link

As an open source compression tool, 7-Zip is a popular tool for making sets of files easier to handle and transfer. The software offers up its own benchmark, to which we report the result.

Gaming Performance 2015

Our 2015 gaming results are still relatively new, but the issue of FCLK settings might play a big role here. At launch, the default setting for the communication buffer between the CPU and PCIe stack was 800 MHz, even though Intel suggested 1000 MHz, but this was because of firmware limitations from Intel. Since then, there is firmware to enable 1000 MHz, and most motherboard manufacturers have this - but it is unclear if the motherboard will default to 1000 MHz and it might vary from BIOS version to BIOS version. As we test at default settings, our numbers are only ever snapshots in time, but it leads to some interesting differences in discrete GPU performance.

Alien: Isolation

If first person survival mixed with horror is your sort of thing, then Alien: Isolation, based off of the Alien franchise, should be an interesting title. Developed by The Creative Assembly and released in October 2014, Alien: Isolation has won numerous awards from Game Of The Year to several top 10s/25s and Best Horror titles, ratcheting up over a million sales by February 2015. Alien: Isolation uses a custom built engine which includes dynamic sound effects and should be fully multi-core enabled.

For low end graphics, we test at 720p with Ultra settings, whereas for mid and high range graphics we bump this up to 1080p, taking the average frame rate as our marker with a scripted version of the built-in benchmark.

Total War: Attila

The Total War franchise moves on to Attila, another The Creative Assembly development, and is a stand-alone strategy title set in 395AD where the main story line lets the gamer take control of the leader of the Huns in order to conquer parts of the world. Graphically the game can render hundreds/thousands of units on screen at once, all with their individual actions and can put some of the big cards to task.

For low end graphics, we test at 720p with performance settings, recording the average frame rate. With mid and high range graphics, we test at 1080p with the quality setting. In both circumstances, unlimited video memory is enabled and the in-game scripted benchmark is used.

Grand Theft Auto V

The highly anticipated iteration of the Grand Theft Auto franchise finally hit the shelves on April 14^th 2015, with both AMD and NVIDIA in tow to help optimize the title. GTA doesn’t provide graphical presets, but opens up the options to users and extends the boundaries by pushing even the hardest systems to the limit using Rockstar’s Advanced Game Engine. Whether the user is flying high in the mountains with long draw distances or dealing with assorted trash in the city, when cranked up to maximum it creates stunning visuals but hard work for both the CPU and the GPU.

For our test we have scripted a version of the in-game benchmark, relying only on the final part which combines a flight scene along with an in-city drive-by followed by a tanker explosion. For low end systems we test at 720p on the lowest settings, whereas mid and high end graphics play at 1080p with very high settings across the board. We record both the average frame rate and the percentage of frames under 60 FPS (16.6ms).

GRID: Autosport

No graphics tests are complete without some input from Codemasters and the EGO engine, which means for this round of testing we point towards GRID: Autosport, the next iteration in the GRID and racing genre. As with our previous racing testing, each update to the engine aims to add in effects, reflections, detail and realism, with Codemasters making ‘authenticity’ a main focal point for this version.

GRID’s benchmark mode is very flexible, and as a result we created a test race using a shortened version of the Red Bull Ring with twelve cars doing two laps. The car is focus starts last and is quite fast, but usually finishes second or third. For low end graphics we test at 1080p medium settings, whereas mid and high end graphics get the full 1080p maximum. Both the average and minimum frame rates are recorded.

Middle-Earth: Shadow of Mordor

The final title in our testing is another battle of system performance with the open world action-adventure title, Shadow of Mordor. Produced by Monolith using the LithTech Jupiter EX engine and numerous detail add-ons, SoM goes for detail and complexity to a large extent, despite having to be cut down from the original plans. The main story itself was written by the same writer as Red Dead Redemption, and it received Zero Punctuation’s Game of The Year in 2014.

For testing purposes, SoM gives a dynamic screen resolution setting, allowing us to render at high resolutions that are then scaled down to the monitor. As a result, we get several tests using the in-game benchmark. For low end graphics we examine at 720p with low settings, whereas mid and high end graphics get 1080p Ultra. The top graphics test is also redone at 3840x2160, also with Ultra settings, and we also test two cards at 4K where possible.

ASUS Maximus VIII Extreme Conclusion

I mentioned at the top of the review that this is the second halo motherboard we’ve tested. Both the ASUS Maximus VIII Extreme and GIGABYTE Z170X-Gaming G1 command a large price but represent the premium product from the two major motherboard players in the industry. For the sale, each side focuses on specific areas:

ASUS Maximus VIII Extreme vs GIGABYTE Z170X-Gaming G1  MSRP $500
Motherboard	ASUS Maximus VIII Exteme	GIGABYTE G170X-Gaming G1
Warranty Period	3 Years	3 Years
Product Page	Link	Link
Price	Amazon US	Amazon US
Size	E-ATX	E-ATX
CPU Interface	LGA1151	LGA1151
Chipset	Intel Z170	Intel Z170
Memory Slots (DDR4)	Four DDR4 Supporting 64GB Dual Channel Up to 3866 MHz	Four DDR4 Supporting 64GB Dual Channel Up to 3666 MHz
Video Outputs	HDMI DisplayPort	HDMI
Network Connectivity	Intel I219-V 3T3R 802.11ac	2 x Killer E2400 Killer AC-1535 2T2R 802.11ac
Onboard Audio	Realtek ALC1150 with ESS ES9023P DAC bypass	Creative Sound Core 3D + JRC NJM2114 + Burr Brown OPA2134
PCIe Slots for Graphics (from CPU)	3 x PCIe 3.0  - x16,  - x8/x8,  - x8/x4/x4	4 x PCIe 3.0 via PLX8747  - x16/x16,  - x16/x8/x8,  - x8/x8/x8/x8
PCIe Slots for Other (from PCH)	1 x PCIe 3.0 x4 2 x PCIe 3.0 x1	3 x PCIe 3.0 x1
Onboard SATA	Six, RAID 0/1/5/10 Two from ASMedia ASM1061	Six, RAID 0/1/5/10 Four via ASM1061, no RAID
Onboard SATA Express	Two, RAID	Three
Onboard M.2	1 x PCIe 3.0 x4 or SATA, RAID 0/1, NVMe	2x PCIe 3.0 x4 or SATA, RAID 0/1, NVMe
Onboard U.2	1 x PCIe 3.0 x4 (switched with M.2)	None
USB 3.1	2 x Type-A (ASM1142) 1 x Type-A (Alpine Ridge) 1 x Type-C (Alpine Ridge)	1 x Type-A (Alpine Ridge) 1 x Type-C (Alpine Ridge) 1 x Type-A (Front Panel bundle) 1 x Type-C (Front Panel bundle)
USB 3.0	4 x Rear Panel 4 via headers	4 x Rear Panel 2 via headers
USB 2.0	- 6 via headers	2 x Rear Panel 4 via headers
Power Connectors	1 x 24-pin ATX 1 x 8-pin CPU 1 x 4-pin CPU	1 x 24-pin ATX 1 x 8-pin CPU
Fan Headers	2 x CPU (4-pin) 4 x CHA/SYS (4-pin)	2 x CPU (4-pin) 5 x CHA/SYS (4-pin)
Notes	Bundled OC Panel	Bundled USB 3.1 Panel Combination air/water heatsink

The big selling points for the Z170X-Gaming G1 are the PLX8747 chip enabling 32 PCIe lanes for 3-way and 4-way SLI, three Killer based network points for DoubleShot-X3 Pro, a combination air/water chipset heatsink, dual M.2, a USB 3.1 front panel, PCIe guards, and a Creative Sound Core 3D audio codec with a Burr Brown op-amp.

The big selling points for the Maximus VIII Extreme are the 3x3 Wi-Fi module, onboard U.2 support, a total of four onboard USB 3.1 ports, an ES9023P audio DAC, a bundled OC Panel, system performance and the BIOS/software package.

Both motherboards are validated with Thunderbolt 3.

It’s an interesting scenario being played out. ASUS wins on the performance side, the BIOS and software are easier to use, and overclocking wins out due to LLC implementation. 3x3 WiFi plus U.2 is hard to ignore on the Extreme as well. But the multi-GPU support of the GIGABYTE via the PLX is the massive plus that can’t be made up elsewhere (and non-GPUs can be used as well).

Both sides have impressive feature sets, and both sides have areas for improvement. If the price is still a factor and the prices of these motherboards decrease over time, if the GIGABYTE ends up $50-75 less expensive in a direct comparison, it would be hard to pass up that saving to spend elsewhere. Under the 100-series platform and Skylake processors, ASUS takes the crown up to dual GPU here, whereas by virtue of support the GIGABYTE motherboard happily takes it for 3-way and 4-way.

I’d happily recommend the ASUS to any performance junkie, but sometimes big performance needs big PCIe, and I’d happily recommend the GIGABYTE in that case. 

Recommended by AnandTech
The ASUS Rampage VIII Extreme Motherboard
For Your Local Performance Junkie, Dual GPU and under

 

Other AnandTech Reviews for Intel’s 6^th Generation CPUs and 100-Series Motherboards

Skylake-K Review: Core i7-6700K and Core i5-6600K - CPU Review
Comparison between the i7-6700K and i7-2600K in Bench - CPU Comparison
Overclocking Performance Mini-Test to 4.8 GHz - Overclocking
Skylake Architecture Analysis - Microarchitecture
Z170 Chipset Analysis and 55+ Motherboards - Motherboard Overview
Discrete Graphics: An Update for Z170 Motherboards - PCIe Firmware Update
Price Check: Intel Skylake i7-6700K and i5-6600K - Latest Skylake Price Check (3/29)

100-Series Motherboard Reviews:
Prices Correct at time of each review

($500) The GIGABYTE Z170X-Gaming G1 Review
($500) The ASUS Maximus VIII Extreme Review (this review)
($250) The ASUS Maximus VIII Impact Review
($240) The ASRock Z170 Extreme7+ Review
($230) The MSI Z170 Gaming M7 Review
($208) The GIGABYTE Z170-UD5 TH Review
($165) The ASUS Z170-A Review
($125) The Supermicro C7H170-M Review

Motherboard Reviews Planned:

For anyone not interested in the $500 motherboard segment, the next one up on the block is the MSI Z170A SLI PLUS, which comes in at $120-130. Stay tuned for that review. We've also got a couple of server focused Skylake boards waiting in the wings.