Introduction and Setup Impressions

The Intel NUC has created a very successful niche for itself in the SFF PC market. It provides us with insights into where the traditional casual / home use desktop market might end up. While vendors such as Logic Supply have taken the Intel NUC motherboard as the base and built effective designs on top of it, companies like Gigabyte have their own take with the BRIX lineup (which has more options compared to the traditional NUC line, including AM-based ones and NVIDIA GPU-equipped units). In this situation, we have Zotac come out with the ZBOX Sphere lineup. A motherboard tracing its origins (like the Intel-based BRIX units) to the Intel NUC, it differentiates itself mainly in its aesthetics. Even though the features like support for a mSATA SSD in addition to the standard 2.5" drive immediately remind users of the NUC, Zotac is itself no stranger to UCFF motherboards and systems. We have seen the Zotac nano xs units predate the NUC, making Zotac a pionner in this domain..Update: Zotac confirmed to us that the motherboard inside the OI520 is based off their existing Haswell-based nano units.

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 Zotac PCs don'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 65 W (19V @ 3.42A) adapter, a US power cord, a Quick Start guide and an user manual. We installed Windows 8.1 Professional x64 for our evaluation purposes.

There is no doubt that the ZBOX Sphere series owes its design aesthetics to the ill-fated Nexus Q. The rear of the unit has been modified a bit to accommodate the motherboard at an angle. Unlike some of the other mini-PCs that we have evaluated, this one ticks the right box in having a USB port on the side. The gallery below takes us around the hardware.

Prior to moving on with the rest of the review, we have a small table that gives an overview of the various systems that we are comparing the ZBOX OI520 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 OI520 when we come to those sections.

Performance Metrics - I

The ZBOX OI520 Plus was evaluated using our standard test suite for low power desktops / industrial PCs. We have recently revamped our benchmark suite (after the publication of the first Intel NUC review). We reran some of the new benchmarks on the original NUC 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 i5-4200U in the ZBOX OI520 has AES-NI support. TrueCrypt is 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 OI520 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.

Storage and Wireless Networking Credentials

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 OI520 Plus obviously suffers here due to the absence of a SSD.

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.

The wireless card performs as well as the 2x2 Intel AC card in the NUC, despite being 1x1 only

HTPC Aspects - Network Streaming and Local Playback

The unique appearance of the ZBOX OI520 makes it a good candidate for use in an entertainment center. The fans are, for the most part, quite silent. Given the specifications, it is quite clear that we are not looking at a fully madVR-capable machine, but one targeted at the average HTPC user or someone looking for a HTPC to put in a second or third room (non-primary HTPC). 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 OI520 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. madVR itself drops plenty of frames to keep up with the playback requirements (which is expected given the system specifications), but those are not related to the refresh rate of the display.

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.

Playback using Adobe Flash is leaner on the resources compared HTML5 streaming. This is likely due to the fact that the HTML5 stream delivers a 720p version which needs scaling in addition to decoding for display on a 1080p screen. In any case, the power numbers for YouTube and Netflix streaming are quite low, similar to the NUCs.

Decoding and Rendering Benchmarks

In order to evaluate local file playback, we concentrate on EVR /EVR-CP, as well as madVR in its default settings. 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). The decoder used is from the LAV filters integrated in MPC-HC v1.7.3. The following table summarizes the GPU usage and power consumption at the wall in various cases. Numbers in bold indicate visible dropped frames. DXVA Scaling in madVR helps in playback of the 720p60 stream, but interlaced high frame rate content seems best suited for playback using EVR-CP / EVR only.

Miscellaneous Aspects and Concluding Remarks

The power consumption at the wall was measured with the display being driven through the HDMI port. In the graphs below, we compare the idle and load power of the ZBOX OI520 Plus with other low power PCs evaluated before. For load power consumption, we ran Furmark 1.12.0 and Prime95 v27.9 together. The unit could have been more power efficient compared to the Intel NUC kit if it had come with a SSD instead of the hard drive.

Given the active nature of the thermal solution, it is no surprise that the unit is able to handle full loading without any throttling. In fact, even after a hour of processor-intensive tasks (30 minutes of full CPU loading + 30 minutes of full CPU and GPU loading), the maximum temperature of the cores was only 71 C (as show in the gallery below).

Coming to the business end of the review, it is heartening to see motherboard / mini-PC vendors sit up and build upon Intel's NUC efforts. The OI520's performance is very similar to the high-end NUC, but it has additional I/O options (extra USB 2.0 ports, card reader etc.). For users looking to get a mini-PC that is not just a plain rectangular box, the ZBOX Sphere OI520 makes for a very good choice. Pretty much the only downside is that the Plus model makes for a questionable choice as it come with hard drives instead of SSDs and only one SO-DIMM slot occupied. Readers would be better off grabbing the non-Plus model and putting in a SSD / two SO-DIMM sticks for better performance.