Introduction and Setup Impressions

Intel's Crystal Well parts (-R series) with integrated eDRAM have arguably been the most interesting products in the Haswell line-up. In the early stages, only Apple had access to these parts. However, since the beginning of 2014, we have seen other vendors roll out products based on the -R series processors. The BRIX Pro (BXi7-4770R) was one of the first products to roll out with Crystal Well in the PC space. With a design reminiscent of the NUC, the focus was more on designing a compact platform rather than providing more features on the hardware side. The -R series processors are all OEM-only, so users have to look to PC manufacturers to get systems based on it. Expandability in terms of adding PCIe cards (such as discrete GPUs and/or wired network adapters) is ruled out, and one has to rely on what the OEM designs into the motherboard. Zotac has taken their full-size mini-PC chassis (similar to the one in the Zotac ID89) and put in a motherboard sporting a Core i7-4770R inside it to create the ZBOX EI750.

Zotac provides both barebones and Plus models, as is customary with all their pre-built PCs. The Plus model comes with a disk drive as well as some DRAM bundled. Our review configuration was the Plus model with the following configuration.

The ZBOX EI750 doesn't come with any pre-installed OS, but we do have a read-only USB key with Windows drivers. In addition to the main unit, the other components of the package include a 120 W (19V @ 6.32A) adapter, a US power cord, plastic stand / base holder for the main unit, a single 2.4 GHz / 5 GHz antenna for the Wi-Fi module, a DVI-to-HDMI adapter, screws for 2.5" HDD installation, a Quick Start guide and an user manual. We installed Windows 8.1 Professional x64 for our evaluation purposes.

The stand-out aspects of the ZBOX EI750 compared to similar mini-PCs include the presence of two Display Port outputs, two GbE LAN ports and an optical SPDIF output. The gallery below takes us around the hardware in the unit.

In the course of our review, we found that the EI750 Plus came up with some disappointing benchmark numbers compared to the BRIX Pro. It was quite obvious that the single-channel memory in the ZBOX was pulling it down. To simulate a typical end-user situation, we augmented the unit with an ADATA mSATA SSD (SX300) boot drive and replaced the original single Crucial SODIMM with 2x 8 GB ADATA SODIMMs having the same CAS latency of 11. The rest of the review will present benchmark numbers for both configurations.

In the table below, we have an overview of the various systems that we are comparing the ZBOX EI750 against. Note that they may not belong to the same market segment. The relevant configuration details of the machines are provided so that readers have an understanding of why some benchmark numbers are skewed for or against the EI750 when we come to those sections.

Performance Metrics - I

The ZBOX EI750 was evaluated using our standard test suite for low power desktops / industrial PCs. We revamped our benchmark suite earlier this year after the publication of the Intel D54250WYK NUC review) We reran some of the new benchmarks on the older PCs also, but some of them couldn't be run on loaner samples. Therefore, the list of PCs in each graph might not be the same.

Futuremark PCMark 8

PCMark 8 provides various usage scenarios (home, creative and work) and offers ways to benchmark both baseline (CPU-only) as well as OpenCL accelerated (CPU + GPU) performance. We  benchmarked select PCs for the OpenCL accelerated performance in all three usage scenarios.

Miscellaneous Futuremark Benchmarks

3D Rendering - CINEBENCH R15

We have moved on from R11.5 to R15 for 3D rendering evaluation. CINEBENCH R15 provides three benchmark modes - OpenGL, single threaded and multi-threaded. Evaluation of select PCs in all three modes provided us the following results.

Performance Metrics - II

In this section, we mainly look at benchmark modes in programs used on a day-to-day basis, i.e, application performance and not synthetic workloads.

x264 Benchmark

First off, we have some video encoding benchmarks courtesy of x264 HD Benchmark v5.0.

7-Zip

7-Zip is a very effective and efficient compression program, often beating out OpenCL accelerated commercial programs in benchmarks even while using just the CPU power. 7-Zip has a benchmarking program that provides tons of details regarding the underlying CPU's efficiency. In this subsection, we are interested in the compression and decompression MIPS ratings when utilizing all the available threads.

TrueCrypt

As businesses (and even home consumers) become more security conscious, the importance of encryption can't be overstated. CPUs supporting the AES-NI instruction for accelerating the encryption and decryption processes have, till now, been the higher end SKUs. However, with Bay Trail, even the lowly Atom series has gained support for AES-NI. The i7-4770R, being the flagship Crystal Well part for Haswell, hasn't been left behind. It does have AES-NI support and TrueCrypt, a popular open-source disk encryption program which can take advantage of the AES-NI capabilities. The TrueCrypt internal benchmark provides some interesting cryptography-related numbers to ponder. In the graph below, we can get an idea of how fast a TrueCrypt volume would behave in the ZBOX EI750 and how it would compare with other select PCs. This is a purely CPU feature / clock speed based test.

Agisoft Photoscan

Agisoft PhotoScan is a commercial program that converts 2D images into 3D point maps, meshes and textures. The program designers sent us a command line version in order to evaluate the efficiency of various systems that go under our review scanner. The command line version has two benchmark modes, one using the CPU and the other using both the CPU and GPU (via OpenCL). The benchmark takes around 50 photographs and does four stages of computation:

• Stage 1: Align Photographs
• Stage 2: Build Point Cloud (capable of OpenCL acceleration)
• Stage 3: Build Mesh
• Stage 4: Build Textures

We record the time taken for each stage. Since various elements of the software are single threaded, others multithreaded, and some use GPUs, it is interesting to record the effects of CPU generations, speeds, number of cores, DRAM parameters and the GPU using this software.

Dolphin Emulator

Wrapping up our application benchmark numbers is the Dolphin Emulator benchmark mode results.

Gaming Benchmarks

The gaming credentials of the Core i7-4770R received a huge marketing boost when the BRIX Pro was distributed as a 'Steam Machine' at the Steam Developers Conference earlier this year. Based on paper specifications alone, the Crystal Well parts should be able to perform much better than any other previous Intel IGP. For the purpose of benchmarking, we chose five different games (Company of Heroes 2, Sleeping Dogs, Tomb Raider, Bioshock Infinite and DiRT Showdown) at three different quality levels.

As someone focusing on HTPCs and multimedia aspects, I rarely get to process gaming benchmarks, even while evaluating GPUs. One of the aspects that I feared was spending lot of time in installing the same games again and again on different PCs under the review scanner. The solution was to go the Steam route. Unfortunately, Steam also likes to keep the game files updated. A quick online search revealed that Steam could make use of an external drive for storing the game executables and downloadable content. With the Steam drive on-the-go use-case being read-heavy, the Corsair Flash Voyager GS USB 3.0 128GB Flash Drive (with read speeds of up to 275 MBps) was ideal for use as a portable Steam drive.

Benchmark Numbers

Despite similar clock speeds and memory configurations, the BRIX Pro manages to have a lead over both ZBOX EI750 configurations in our gaming benchmarks.

Network & Storage Performance

We have recently started devoting a separate section to analyze the storage and networking credentials of the units under review. On the storage side, one option would be repetition of our strenuous SSD review tests on the drive(s) in the PC. Fortunately, to avoid that overkill, PCMark 8 has a storage bench where certain common workloads such as loading games and document processing are replayed on the target drive. Results are presented in two forms, one being a benchmark number and the other, a bandwidth figure. We ran the PCMark 8 storage bench on selected PCs and the results are presented below.

The presence of a mSATA SSD greatly increases the usability of the unit if the workloads have major dependence on storage performance.

On the networking side, we restricted ourselves to the evaluation of the WLAN component. Our standard test router is the Netgear R7000 Nighthawk configured with both 2.4 GHz and 5 GHz networks. The router is placed approximately 20 ft. away, separated by a drywall (as in a typical US building). A wired client (Zotac ID89-Plus) is connected to the R7000 and serves as one endpoint for iPerf evaluation. The PC under test is made to connect to either the 5 GHz (preferred) or 2.4 GHz SSID and iPerf tests are conducted for both TCP and UDP transfers. It is ensured that the PC under test is the only wireless client for the Netgear R7000. We evaluate total throughput for up to 32 simultaneous TCP connections using iPerf and present the highest number in the graph below.

In the UDP case, we try to transfer data at the highest rate possible for which we get less than 1% packet loss.

Despite the presence of a 1x1 802.11ac card instead of a 2x2 that some of the other mini-PCs employ, the unit manages to pull in leading numbers in our Wi-Fi testing. The Intel AC7260 seems to be suffering from a driver bug making it unable to make use of the 2x2 capabilities. That said, the antenna position in the EI750 is better than the OI520 which carries the same mini PCIe card. That sid, considering the premium nature of the PC, it would have been good to have a 2x2 card such as the Intel AC7260 or one from Broadcom in the long run for better performance. However, the unit does make up for this in the wired department by having two GbE LAN ports. This opens up a number of interesting applications which we will talk about in the final section.

ZBOX EI750 as a HTPC

The ZBOX EI750 has a much better acoustic profile compared to the BRIX Pro (thanks to the larger chassis, which, in turn, allows for a fan with a larger diameter). But, it is still noisy for HTPC use. However, it does have the credentials for a gaming HTPC, where noise is not that much of a concern. The Core i7-4770R should be capable enough for madVR when the algorithms and video stream resolutions are restricted. There are two HTPC aspects that we will explore in this section, one related to network streaming (OTT services), and the other related to local file playback. Prior to that, we have a small sub-section dealing with refresh rate accuracy.

Custom Refresh Rates

We found last year that Haswell provided excellent display refresh rate accuracy, and reconfirmed that in multiple Haswell mini-PC reviews. Our experience with the ZBOX EI750 was also flawless.

The gallery below presents some of the other refresh rates that we tested out. The first statistic in madVR's OSD indicates the display refresh rate.

Network Streaming Efficiency

Evaluation of OTT playback efficiency was done by playing back our standard YouTube test stream and five minutes from our standard Netflix test title. Using HTML5, the YouTube stream plays back a 720p encoding, while Adobe Flash delivers a 1080p stream. The power consumption at the wall as well as the GPU usage while playing them on Mozilla Firefox are provided in the graphs below.

Netflix streaming evaluation was done using the Windows 8.1 Netflix app. Manual stream selection is available (Ctrl-Alt-Shift-S) and debug information / statistics can also be viewed (Ctrl-Alt-Shift-D). Statistics collected for the YouTube streaming experiment were also collected here.

Decoding and Rendering Benchmarks

In order to evaluate local file playback, we concentrate on EVR-CP and madVR. We already know that EVR works quite well with the Intel IGP for our test streams. Under madVR, we used the default settings initially. madVR also has an option to utilize the hardware scaler that is specific to Intel HD Graphics (instead of the specific algorithms that can be configured via its interface). Other than these, we also put together a 'madVR stress configuration' with the upscaling algorithms set to Jinc 3-tap with anti-ringing activated and the downscaling algorithm set to Lanczos 3-tap, again with anti-ringing activated. The decoder used is from the LAV filters integrated in MPC-HC v1.7.3.

These results present data points additional to whatever we had for the BRIX Pro. The PC has no trouble, as expected, with EVR-CP for any of our test streams. Even madVR works in the default and DXVA scaling configurations. Problems start to appear only for 60 fps progressive streams as well as 4K streams when advanced madVR scaling algorithms are chosen.

Miscellaneous Aspects & Final Words

The power consumption at the wall was measured with the display being driven through the DVI-HDMI port. In the graphs below, we compare the idle and load power of the ZBOX EI750 Plus with other low power PCs evaluated before. For load power consumption, we ran Furmark 1.12.0 and Prime95 v27.9 together. The addition of a SODIMM and an extra mSATA SSD in our custom configuration obviously drives up the idle power consumption numbers a bit, a penalty the user needs to pay for better performance. However, the load power consumption numbers show an inversion because the extra RAM causes heavier throttling, bringing down the load power numbers in steady state below that of the Plus configuration.

Thermal Performance

Given the active nature of the thermal solution and the size of the chassis, it would have been fair to expect the unit to be able to handle full loading of the CPU and GPU without issues. Unfortunately, just like the BRIX Pro, the unit throttles under heavy artificial loading (Prime 95 + Furmark). Unlike the BRIX Pro, the unit even throttles under pure CPU loading. The gallery below presents the different cases.

Only the pure GPU loading case doesn't throttle. This is definitely a bit disappointing, but, only from a purely engineering standpoint. The usual use-cases rarely stress the CPU and GPU to these limits. Intel is also heavily promoting the scenario design power metric for thermal design. The CPU and GPU don't do as much work as in our power virus test.

Concluding Remarks

I have been using the unit as a virtualization platform, running a Windows 7 VM and a CentOS 6.2 VM simultaneously, each of them with a dedicated wired network link. The in-built Wi-Fi is used for the host OS. The ability to put in up to 16 GB of RAM and back up the mSATA SSD with the already supplied 1 TB 2.5" HDD provides more than enough storage. With the VMs inactive, I have been using this as a compact and silent low-power software development machine with higher performance compared to other Zotac ZBOX units. Unfortunately, the flagship GPU is not utilized heavily in these scenarios. In none of these applications did we see the unit throttle due to heavy loading.

Coming to the business end of the review, we are very happy to see Zotac putting in the Iris Pro in a more feature-rich machine compared to the BRIX Pro. The unit can drive three displays simultaneously without daisy-chaining. The USB ports are more spaced out and we also have a card reader built into the unit. Most importantly, the two wired GbE ports open up various interesting applications for this powerful mini-PC. Despite the throttling aspects of the design and the fact that the BRIX Pro manages to surpass the EI750 in almost all of our benchmarks, we can recommend the Core i7 equipped ZBOX EI750 for most practical applications. It also goes without saying that end users are better off with a barebones model and choosing their own SSD and memory configurations.