Introduction and Setup Impressions

Over the last couple of years, the ultra-compact form factor (UCFF) has emerged as one of the bright spots in the troubled PC market. Intel kickstarted the category with their Sandy Bridge NUC kits in early 2013. Recognizing the popularity of this segment, other vendors also began to promote similar products. GIGABYTE targets this market segment with an extensive lineup of products under the BRIX brand. We recently looked at the high-end Haswell BRIX, the GB-BXi7-4500. The focus of this review is on the opposite side of the spectrum - they Bay Trail-D Celeron J1900-based GB-BXBT-1900. As a note, due to GIGABYTE's regional marketing policies, this model is currently not being sold in the North American market, but targets price conscious buyers everywhere else.

Similar to other BRIX units, the BXBT-1900 comes barebones. An important point to note is that, unlike the higher-end BRIX units, the BXBT-1900 doesn't support mSATA drives. The support for 2.5" drives makes the z-height a bit more than the BRIX s (pure mSATA) models that we have looked at before. The dimensions (56.1 mm x 107.6 mm x 114.4 mm) otherwise conform to the smallest possible BRIX units (29.9 mm x 107.6 mm x 114.4 mm). Another point of difference is the presence of only one SO-DIMM DDR3L slot rated for operation at 1333 MHz (compared to the dual 1600 MHz-capable slots in the Haswell-based units). We configured the review unit to end up with the following components:

GIGABYTE GB-BXBT-1900 Specifications
Processor	Intel Celeron J1900 (4C/4T x 2.00 GHz (2.41 GHz Turbo), 22nm, 2MB L2, 10W)
Memory	1 x 4GB DDR3L-1600
Graphics	Intel HD Graphics
Disk Drive(s)	Samsung SSD 840 EVO 120GB 2.5" SSD
Networking	1x Gigabit Ethernet, 1x1 802.11n/Bluetooth  mPCIe
Audio	Capable of 5.1/7.1 digital output with HD audio bitstreaming (HDMI)
Operating System	Retail unit is barebones, but we installed Windows 8.1 Pro x64
Pricing (As configured)	~$170 (barebones) + $129 (DRAM + 2.5" SSD)
Full Specifications	GB-BXBT-1900 Specifications

The BXBT-1900 kit doesn't come with any pre-installed OS, but does come with a driver CD. In the higher-end kits, GIGABYTE has moved to USB keys for the drivers. In any case, we ended up installing the latest drivers downloaded off GIGABYTE's product support page. In addition to the main unit, the other components of the package include a 30 W (12V @ 2.5A) adapter, a US power cord, a VESA mount (along with the necessary screws), a driver CD and a quick-start guide.

The gallery below takes us around the hardware in the unit.

In order to complete our build, we opted for a 2.5" Samsung SSD 840 EVO (with the read performance bug recently fixed) and a single Crucial CT51264BF160B (Micron 8KTF51264HZ-1G6J1) 4 GB SO-DIMM.

In the table below, we have an overview of the various systems that we are comparing the BXBT-1900 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 BXBT-1900 when we come to those sections.

Comparative PC Configurations
Aspect	GIGABYTE GB-BXBT-1900	Intel D54250WYKGIGABYTE GB-BXi5G-760Intel D54250WYKHGIGABYTE GB-BXi7-4770R (2)GIGABYTE GB-BXi7-4500ECS LIVAZotac ZBOX OI520 Plus
CPU	Intel Celeron J1900	Intel Core i5-4250U
GPU	Intel HD Graphics	Intel HD Graphics 5000
RAM	Crucial CT51264BF160B (Micron 8KTF51264HZ-1G6J1) 11-11-11-28 @ 1600 MHz 1x4 GB	Crucial CT51264BF160B (Micron 8KTF51264HZ-1G6J1) 11-11-11-28 @ 1600 MHz 2x4 GB
Storage	Samsung SSD 840 EVO (120 GB, 2.5in SATA 6Gb/s, 19nm, TLC)	Intel SSD 530 Series (180 GB, PCIe Module mSATA 6Gb/s, 20nm, MLC)
Wi-Fi	Realtek 8723BE Wireless LAN 802.11n (1x1 802.11n - 150 Mbps)	Intel Dual Band Wireless-AC 7260 (2x2 802.11ac - 867 Mbps)
Price (in USD, when built)	$292	$680

Performance Metrics - I

The GIGABYTE GB-BXBT-1900 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. These scores are heavily influenced by the CPU in the system. The Celeron J1900 is obviously not in the league of the Haswell CPUs. To make a relevant comparison - it indeed scores better than the Celeron N2806 (Bay Trail-M) in the ECS LIVA. However, unlike the LIVA unit, the BXBT-1900 is not passively cooled.

Miscellaneous Futuremark Benchmarks

3D Mark 11's extreme benchmarking mode has always consistently failed with Bay Trail for us. Therefore, the only frame of reference we have is the entry level score in the graph below.

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. This is simply a test of CPU performance. As expected, the Celeron J1900 with active cooling performs about twice as better as the passively cooled LIVA, but can't match the Haswell CPUs in the other mini-PCs.

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. The presence of four distinct cores helps the unit move to the middle of the pack in the decompression ratings.

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 Silvermont, even the lowly Atom series has gained support for AES-NI in some SKUs. Unfortunately, AES-NI is not a feature available in Bay Trail-D. AES operations have to be done in software. TrueCrypt, a popular open-source disk encryption program can take advantage of the AES-NI capabilities, but fall back to a software implementation in the absence of AES-NI. 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 GIGABYTE GB-BXBT-1900 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. This is again a test of the CPU capabilities, and the trend seen in earlier CPU-focused workload graphs are evident here also.

Networking & 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 Samsung SSD 840 EVO is the same model that was used in the BRIX Pro. While there is not much to separate them in the storage subsystem score, there is quite a bit of difference in the storage bandwidth. Since the storage bandwidth workloads are real-world traces, it makes sense that the CPU can act as a bottleneck. This is the reason why we have a gap of more than 60 MBps between the two systems. Effectively speaking, pairing the Samsung SSD 840 EVO with a Celeron J1900 system will not expose the full benefits of the SSD in real-world situations. It goes without saying that the SSD does make the system more responsive by removing disk I/O bottlenecks compared to hard drives (such as the one used in the ZBOX OI520 PLUS).

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 BXBT-1900 uses the same Realtek RTL8723BE 1x1:1 802.11n / BT combo that we saw in the BXi7-4500 earlier this month. The slight differences in the throughput numbers above can be attributed to antenna placement. In any case, a single stream 802.11n card is the bare minimum that today's PCs can ship with. Given the low price target for this Bay Trail system, we believe GIGABYTE can be excused for bundling such a card.

HTPC Credentials

The GIGABYTE GB-BXBT-1900 does have a small fan (as shown in one of the pictures in the hardware gallery on the first page), but it is quite inaudible compared to even the quiet GB-BXi7-4500. As such, for users unwilling to digest the premium pricing of passively cooled PCs at this performance level, the BXBT-1900 is an ideal choice. The only issue, as we will see in this section, is that the HTPC capabilities offered do not go beyond what the lower priced ECS LIVA can deliver while being fanless. Since both are based on Bay Trail chipsets, this is not an issue.

Another aspect that HTPC users need to keep in mind while considering Bay Trail systems is the HD audio bitstreaming capability. The hardware is indeed capable, and we do get Dolby Digital Plus bitstreaming with the Windows 8.1 Netflix app. However, XBMC and other commercial software Blu-ray players are unable to bitstream DTS-HD and TrueHD audio on Windows 8.1 due to a missing software component for the Bay Trail chipset. OpenELEC (and other such bootable operating systems) has no problems, though, because it doesn't rely on the Windows component (obviously) for HD audio support.

Refresh Rate Accuracy

AMD and NVIDIA have historically been able to provide fine-grained control over display refresh rates. The default rates are also quite accurate. Intel used to have an issue with 23 Hz (23.976 Hz, to be more accurate) support, but that was resolved with the introduction of Haswell. As expected, the GIGABYTE GB-BXBT-1900 has no trouble with refreshing the display appropriately in the 23 Hz setting.

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. Note that only NVIDIA exposes GPU and VPU loads separately. Both Intel and AMD bundle the decoder load along with the GPU load. The following two graphs show the power consumption at the wall for playback of the HTML5 stream and the Adobe Flash stream in Mozilla Firefox v32.0.1. For HTML5 streaming, the GPU load averaged around 36.96%, while it was 24.31% for the Flash version.

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. The GPU load averaged around 4.74%.

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 even with the Intel IGP for our test streams. Given our results from the evaluation of ECS LIVA, we decided to test only EVR-CP with DXVA2 native decoding for the BXBT-1900. The decoder used was LAV Filters bundled with MPC-HC v1.7.7.

GIGABYTE GB-BXBT-1900 - Decoding & Rendering Performance
Stream	EVR-CP
	GPU Load (%)	Power (W)
480i60 MPEG2	24.56	8.02
576i50 H264	45.74	8.89
720p60 H264	63.79	10.44
1080i60 MPEG2	82.65	12.25
1080i60 H264	93.68	13.32
1080i60 VC1	89.07	12.83
1080p60 H264	76.63	11.49
1080p24 H264	32.99	9.38
4Kp30 H264	91.91	12.46

Entries in bold indicate visible dropped frames. For non-4K and non-interlaced material, the system has no trouble keeping up with the playback. The target market for this type of system will probably not be interested in anything other than vanilla 1080p24 content, and for those folks, the system can act as a good HTPC with EVR-CP as the renderer.

Power Consumption & Thermal Performance

The power consumption at the wall was measured with a 1080p display being driven through the HDMI port. In the graphs below, we compare the idle and load power of the GIGABYTE GB-BXBT-1900 with other low power PCs evaluated before. For load power consumption, we ran Furmark 1.12.0 and Prime95 v27.9 together. The numbers are not beyond the realm of reason for the combination of hardware components in the machine.

As expected, the power consumption numbers closely track the performance of the system. The BXBT-1900 might be on the lower end of the performance spectrum, but it is beaten only by the passively cooled ECS-LIVA in the power consumption numbers.

The active cooling for the SoC in the system ensures that the thermal performance is good. We don't see any thermal throttling and the temperatures are well within specifications even when the system is subject to power viruses. The various clocks in the system as well as the temperatures within the unit are presented below. We start with the system at idle, followed by 30 minutes of pure CPU loading. This is followed by another 30 minutes of both CPU and GPU being loaded simultaneously. After this, the CPU load was removed, allowing the GPU to be loaded alone for another 30 minutes.

The frequency characteristics above indicate that the CPU cores clock in at the maximum turbo rate of 2.41 GHz for the entire 1 hour duration of CPU loading. With the CPU load removed, the frequency of the cores drops down to around 1.3 GHz. The GPU clock remains at a steady 800 MHz under full loading. With both CPU and GPU loaded, the core temperature is only around 65 C, quite far from the maximum junction temperature of 105 C. All in all, the thermal design is excellent, making us wonder what could be achieved with a fanless system.

Final Words

After putting the GB-BXBT-1900 through our mini-PC evaluation routine, we are glad to obtain additional data points that reflect what can be obtained from a system targeted towards price-conscious consumers. GIGABYTE builds upon Intel's NUC ecosystem successfully by presenting a Bay Trail alternative to consumers. Our only 'complaint' is the fact that the system is not available in the North American market (where the fanless Celeron N2807-based system is marketed instead of the BXBT-1900).

Pretty much the only downside of the unit is the bundled 802.11n WLAN component. Even considering the price-point pressures, GIGABYTE could have provided a single-stream 802.11ac card. On the plus side, the BIOS effortlessly handles overclocking transparently. The SO-DIMM we configured with was auto-clocked at 1600 MHz, despite the system's official 1333 MHz specification. The cores were also able to sustain the maximum frequency of 2.41 GHz without any user configuration. On a subjective note, the fan noise is pretty much non-existent.

All in all, GIGABYTE has managed to deliver the right balance of price, power, size and thermal / acoustic design in the GB-BXBT-1900 for the sub-$300 market.