Video decoding, 120Mb HEVC
It’s strange, but desktop computers have been stagnant for over twenty years. In most cases, they are still built on the ATX standard in “oversized“ towers. From a rational point of view, however, such a concept should be marginal and replaced by SFF. A traditional PC can be tiny, powerful, and silent at the same time. And its equipment does not have to limit you.
Large motherboards with loads of expanding slots once had their justification. On the first ATX boards, there were not many integrated things, except for the chipset. The necessity was not only to add basic components such as graphics cards, audio cards, and network cards, but it was not unusual to see a USB controller or cards with serial/parallel interface in the slots too. Everything is now on-board, and the most common thing to add is a graphics card, so the mini-ITX format with one PCIe ×16 slot will satisfy the needs of the vast majority of players. Sure, there will also be users who do not like the modest options for expansion, but we are probably talking about a minority.
The purpose of this article is not to discredit ATX platform. It is still suitable for some atypical use, in extremely powerful configurations with multi-GPU, for example. Also, cryptocurrency is becoming popular, which may exploit several graphics cards, but this is often solved by special cases and boards. Skylake-X processors can also profit from a bigger computer due to their need for enormous power (and cooling). The same thing can be said about servers with massive disk arrays. However, these are not configurations that we normally see at home, although large computers are still everywhere, and unfortunately also in offices. Why do we have to oversize the volume of those cases 50-times?
As part of the project to support SFF (small form factor), also out of the embedded segment, we have built and tested one such sample. We did encounter some minor complications, but that could be expected since the demand on development and optimizations of this platform is small compared to mainstream.
Which components and why
The motherboard is Mini-STX which is the smallest format supporting full-featured desktop processors – so far only those from Intel. The choice of these boards is, in any case, still quite limited, but Gigabyte GA-H110MSTX-HD3 is very well equipped and has good availability in stores.
Two SO-DIMM slots (with DDR4 RAM up to 32 GB/2400 MHz), two SATA 3 connectors and two M.2 connectors, one for Wi-Fi and one for SSD (including NVMe). CPU_fan connector has also one extra friend… for the system cooling (4-pin).
Worth mentioning are some external connectors as well, three 5-gigabit USB 3.1 Gen 1 Type A (for 2.0 there’s internal header available too) and 3.1 Type C. Together, we have six USB ports, which should be enough for the needs of a desktop.
There are two digital video outputs, HDMI (1.4b) and DisplayPort 1.2 make 3840 × 2160 px at 60Hz possible even for iGPUs of Kaby Lake processors. At the same time, Gigabyte, as one of the few manufacturers, did include D-Sub. This analogue output may come in handy. Just like the serial port RS232 (DB9). Although it is part of the package, its assembly is optional. Just the two-channel sound card can be a little deficiency.
When choosing a processor, we were struggling a bit with the outdated chipset. H110 does not have his successor yet. Perhaps H310 will appear on the January CES, but it will take a while till it gets to finished boards. That’s why we chose Core i5-7400 instead of Core i3-8100. Normal variant with TDP 65 W and not limited multiplier. Its thermal power is the maximum that the used board (with 3-phase power supply circuit) supports. And as you will see in the tests, this limit is justified.
However, Coffee Lake has not brought any significant changes for this use (it has just much better price/performance ratio), and the iGPU is still HD 630. This is definitely enough for multimedia use – 4K movie acceleration and occasional encoding – even for playing older games (or new games with reduced level of details, and lower resolution).
The key feature is the CPU cooler. Ideal would be some with a height of 5 cm. Most of other interesting coolers have exceeded this measure, and the smaller ones that could manage are Noctua NH-L9i with 37 mm, and Scythe Kodati rev. B. Both will do. The advantage of Kodati is the fan under the ribs which brings more air around the socket, but it is also smaller than the one that comes with NH-L9i, so it would be best to buy some extra piece for the intake.
Silicon Power now offers a great deal of memory. Remarkable are SP004GBSFU240N02 modules which are manufactured by Samsung (including PCBs) for SP. These are single-ranks with 2400 MHz and CL17 (at 1.2 V). The price of 48 euros per 4GB module is very tempting. 2133MHz with CL15 costs almost the same. Even though, it is a difficult to choose because lower frequency comes with faster timing. The latency of our high-clocked modules is 63 ns.
Silicon Power also impressed with their new SSD – A55. Finally, a low-end (especially the price) that has a larger portion dedicated for the SLC block. Most of the cheap 240 – 256GB disks fall to low speed after few seconds when writing large files, after writing 3 – 5 GB the A55 held up to a minimum of 30 GB (and probably even more, RAM disk capacity limited us). We talk about ~ 450 MB/s. However, it struggles with transfer of tiny files (12 – 59 kB). It takes about two times longer than with models from different manufacturers. Thus, the random access time is 0.048 ms (measured with 512 B blocks). Although you will not notice the difference in OS or application responses. Everything moves and loads really smoothly.
We used a case from Akasa. This company specialize in cases for small configurations and you can tell that outright. The Cypher ST layout is well designed in a comprehensive way. We just think that this case lacks a bit of quality processing and a sense for details. It is solid enough, which was pretty much expected with these dimensions (193 × 153 × 67mm) and 0.9 mm thick sheets. The problem is with mating of individual parts that exceed the measures that they should not. You can notice this even in the photos if you look carefully. However, it is more or less about aesthetics. The case will do fine, of course. You can use it in four positions. Two vertical in height with VESA (100 × 100 mm), the third is also vertical but in width, and the traditional horizontal.
The surface is dull and the look is nice – decent (what do you think?). The casing is relatively airy, only a dust filter is lacking near the perforation next to the CPU cooler. Even some magnetic one would do.
Expansion connectors are a big plus. There is a space for 2× DB9, RS232 connector is still used to communicate with analytics units or cash registers. Additionally, there are 2× USB 2.0 connectors and a pair of holes for Wi-Fi external antennas.
The power supply is the same as in laptops – through an AC adapter. For testing, we used Great Wall which comes along with the case. We cannot guarantee its quality, but we can say that it does not produce any annoying sounds. Its power is 120 W. That is approx. 50% more than we need.
| Component | Brand and model | Price |
| Motherboard | Gigabyte GA-H110MSTX-HD3 | 102 eur |
| Processor | Intel Core i5-7400 (3 – 3.5 GHz) | 165 eur |
| CPU cooler | Noctua NH-L9i | 40 eur |
| RAM | Silicon Power SP004GBSFU240N02 (2× 4 GB) | 96 eur |
| SSD | Silicon Power A55 (256 GB) | 85 eur |
| Case | Akasa Cypher ST | 40 eur |
| Power supply | Great Wall GA120SD1-19006320 (120 W) | 20 eur |
| ---------------------------------------- | ~ 548 eur |
It’s strange, but desktop computers have been stagnant for over twenty years. In most cases, they are still built on the ATX standard in “oversized“ towers. From a rational point of view, however, such a concept should be marginal and replaced by SFF. A traditional PC can be tiny, powerful, and silent at the same time. And its equipment does not have to limit you.
Assembly: tight but fast
The installation of components is more comfortable than in large cases. Everything is handy and there is only a minimum of cables. The most laborious part is installation of the processor (its cooler) and memory.
Getting the board into the case was not as easy as it seemed. Akasa clearly did not count with the D-sub on the board, which slightly exceeds. This means that the original 147 mm turned into 153.6 mm. You simply need to bend the rear panel to make things fit into the I/O shield. This is the first thing to improve – make the rear panel removable.
We are used to connect front panel elements individually in big computers. Here are all things merged into one connector and you can connect either everything or nothing. This connector is similar to USB (it is just a bit smaller). The advantage is that you do not have to study the manual, and it is more comfortable. However, you need to adjust the cable if you do not want LED. That is not very user-friendly and you lose your warranty by doing it.
The system fan is connected via a three-pin connector, which is a bit of a shame because it does not allow PWM control. The format is 50 × 10 mm and the fan produces strange (but relatively quiet) “snarling“.
One of the remaining things is connecting drives. It’s easy with M.2 – plug in and you’re ready to go. For conventional 2.5″ drives, it’s important to connect SATA before plugging them into a 4-pin connector (similar to the ones that previously powered FDD drives). Then you can mount a disk (or two disks/SSD) to a small elegant holder. The only thing that is missing is an anti-vibration grip, but we presume that there will not be many HDD users.
After connecting disks, you’re done. The construction of this computer does not take more than 10 minutes.
It’s strange, but desktop computers have been stagnant for over twenty years. In most cases, they are still built on the ATX standard in “oversized“ towers. From a rational point of view, however, such a concept should be marginal and replaced by SFF. A traditional PC can be tiny, powerful, and silent at the same time. And its equipment does not have to limit you.
Tuning and test procedures
A bit more challenging was to optimize the cooling system to make it as efficient as possible (means decent performance at a tolerable noise level). Especially if you want your computer to work at maximum power.
With the exception of XMP memory settings, we started to test with factory settings, and the power meter subtracted around 81 W. However, this was too much for the power supply circuit. While the CPU (no delid) was fine, VRM reached its limits. Upon reaching 97 °C, the system drastically decreased the multiplier to 8 (ie from 3300 MHz to 800 MHz) and even a maximum flow did not help. Some VRM heatsink would come in handy, but as far as we know only Asrock H110M-STX has it (the only STX with VRM heatsink?). In our case, the most reasonable solution was undervolting of the core. The lowest fully-stable voltage was 0.9 V – 20 watts less and lower VRM temperatures. Now, let’s take a look at how orientation of the case affects cooling efficiency. The fan of the CPU cooler was set to 7 V (~ 1663 rpm) as well as system cooling (~ 2330 rpm). At such speed, the system fan raised the overall noise level by only 0.2 dBA. Of course, we analysed how much it influenced the cooling performance and if it is necessary in the first place. You can find the results (in every possible position) in the charts:
The results show that it is most effective to choose the horizontal position and that the system fan is “useless“. It would certainly be more useful with higher flow, but it would also be the loudest part of the configuration and we do not want that. All other tests were therefore carried out with the case horizontally and without the system fan.
The PWM control curve was a compromise between the lowest noise possible and such MOSFETs heating that would allow stable performance of the computer even in environment with a higher ambient temperature, up to 28 °C (we tested with 21 – 21.3 °C).
We measured the noise level from a distance of approximately 25 cm. The noise level meter Reed R8080 was pointed diagonally to the cooling grid. For more accuracy, we took 30 samples and put the average value to the charts.
The third to seventh chapters capture CPU, chipset and VRM temperatures, noise levels, and power consumption with different load levels. From the extreme load of LinPack with AVX in IntelBurnTest, through the compression of photos in Zoner Photo Studio 18, playing a video with DXVA in Media Player Home Cinema (v1.7.13), to idle stage on Windows 10 desktop. Each of the tests lasted for 900 seconds – the time needed to stabilize the temperatures. We subtracted the consumption values during the last 5 minutes, and the final number in the charts is the average value of 150 samples.
We used Shuttle NC03U5 in the tests to have something to compare our configuration to. It should be emphasized, however, that our build is two times larger. Performance tests were carried out also only for a better orientation because of different memory modules and different graphics drivers (in our configuration we used 23.20.16.4877 WHQL that was released on December 1). For detailed info about performance tests (8th – 9th chapter), check this stand-alone article.
It’s strange, but desktop computers have been stagnant for over twenty years. In most cases, they are still built on the ATX standard in “oversized“ towers. From a rational point of view, however, such a concept should be marginal and replaced by SFF. A traditional PC can be tiny, powerful, and silent at the same time. And its equipment does not have to limit you.
In burn
It’s strange, but desktop computers have been stagnant for over twenty years. In most cases, they are still built on the ATX standard in “oversized“ towers. From a rational point of view, however, such a concept should be marginal and replaced by SFF. A traditional PC can be tiny, powerful, and silent at the same time. And its equipment does not have to limit you.
Image conversion from RAW to JPEG
It’s strange, but desktop computers have been stagnant for over twenty years. In most cases, they are still built on the ATX standard in “oversized“ towers. From a rational point of view, however, such a concept should be marginal and replaced by SFF. A traditional PC can be tiny, powerful, and silent at the same time. And its equipment does not have to limit you.
Video decoding, 120Mb HEVC
It’s strange, but desktop computers have been stagnant for over twenty years. In most cases, they are still built on the ATX standard in “oversized“ towers. From a rational point of view, however, such a concept should be marginal and replaced by SFF. A traditional PC can be tiny, powerful, and silent at the same time. And its equipment does not have to limit you.
Idle (W10 desktop)
It’s strange, but desktop computers have been stagnant for over twenty years. In most cases, they are still built on the ATX standard in “oversized“ towers. From a rational point of view, however, such a concept should be marginal and replaced by SFF. A traditional PC can be tiny, powerful, and silent at the same time. And its equipment does not have to limit you.
Practical performance tests: transcoding and Mafia II
Frame times
It’s strange, but desktop computers have been stagnant for over twenty years. In most cases, they are still built on the ATX standard in “oversized“ towers. From a rational point of view, however, such a concept should be marginal and replaced by SFF. A traditional PC can be tiny, powerful, and silent at the same time. And its equipment does not have to limit you.
Synthetic performance tests: Cinebench and 3DMark
It’s strange, but desktop computers have been stagnant for over twenty years. In most cases, they are still built on the ATX standard in “oversized“ towers. From a rational point of view, however, such a concept should be marginal and replaced by SFF. A traditional PC can be tiny, powerful, and silent at the same time. And its equipment does not have to limit you.
Conclusion
The project focused on building a tiny, efficient, and silent computer is behind us. Current trends in CPU world are not as much about raw power as they used to be, but rather about consumption and efficiency. That creates a unique opportunity to put a “lot of performance“ into a small case and make it work really well and without noise.
We used 65W Core i5-7400 (without T), you can try Core i7-8700 as soon as STX boards ready for Coffee Lake are released. We believe that the attractiveness of the SFF format and its wider expansion will increase even more after Radeon’s upcoming migration to Intel’s processors.
From the tests, we know where the biggest reserves are. In the case of boards, it is VRM cooling which is considerably more limiting factor than processor cooling. We are tempted to claim that with a well-designed power supply circuit, (its cooling included) even some 100W CPU after delid could survive in Akasa Cypher ST (and without any terrible noise).
If you get the impression that from now on we will test only small computers/components, do not worry. We remain loyal to “big toys“. It’s our passion. But when we combine reason and comfort, we must say that a computer that is nicely hidden behind the monitor, without too many cables, that is easy to build, and also more ecological… It is a good deal.
We will be happy if you let us know what you think about small vs. large desktops. Or ask anything that you want to know and we that did not include here. You can also give us some tips on what to improve, and maybe even bring some new ideas to the world of small computers. One thing is certain, if we push minimalist components to the edge of the interest, they will be far from perfection, and constant improvement and their prices will not be very attractive either.