DFI PCSF51 Review: A Credit Card Sized Ryzen Powered Mini PC
DFI PCSF51: Power Consumption, Thermals And Our Conclusion
DFI PCSF51: Power - Friend Or Foe?
Power is a double-edged sword for users of the DFI PCSF51. On the one side, the little Ryzen SBC sips the juice, meaning it won't have a big impact on your household power consumption, even if it is running 24/7. However, we suspect that its SoC is run so far down the power curve that it isn't performing optimally. To provide some background to that assertion, AMD says that the Ryzen Embedded chip in this SBC, the Ryzen R2514 has a TDP range of 12-35W. DFI has set it right at the bottom of that range.Being at the bottom of the TDP range seems to have a worse impact on the GPU than the CPU. Throughout our testing, the CPU would run at its advertised base frequency of 2.1GHz when required, but the GPU would run pretty consistently in the 400 to 450MHz range. We never saw the GPU boost up to the 1.2GHz, which is supposed to be within its capabilities. It wasn't thermally throttling with the large passive heatsink or active cooler either, it was just power limited.
So, we know that the SoC is configured for a 12W power envelope, according to DFI. Doing some power measurements from the wall, however, showed the entire PCSF51 SBC and its included power brick consumed about 15W when idling, which rose to about 20W when active in light productivity or browsing. Both 4K and 1080p video streaming moved the board power consumption up to 24W. The same 24W was recorded in gaming and the various benchmarks we ran.
DFI PCSF51 Thermals
In the intro, we mentioned that the 'standard' passive heatsink wasn't up to the demands of our more intense testing. Using the smaller passive heatsink, we would quite quickly hit toasty temperatures, which caused some throttling. The larger (120mm) passive heatsink caused no such issues, and on an open desk setup (22°C ambient) the hottest CPU temperature recorded by the internal sensor was a little over 74°C. From the outside, as measured by a FLIR IR camera, from about a foot away you can see the hot spot of 51.2°C recorded. This was recorded under load when the on-board thermal sensor said the core temperature was in the 60°C to 70°C range.
Using the active fan cooler resulted in a more compact solution, but the 3,000RPM fan was irritating, and we were happy with the bigger passive unit. DFI is looking at lower RPM fans, so if you are interested, you can check in with them about availability. We think a 1,000RPM fan, with all else being equal, will probably be sufficient.
DFI PCSF51: Our Conclusion
It was enjoyable to use the DFI PCSF51 'Industrial Pi' simply for the feat of cramming AMD Ryzen and Radeon technology with Microsoft Windows 10 into a credit-card sized device. Moreover, in our usage scenario as a silent HTPC it worked nicely. 4K60 streaming videos ran smoothly with no dropped frames (we used 300Mbps wired broadband during testing) and lesser quality video was no problem at all. The unit's decent showing in PCMark 10 also provides evidence that it is fine for light productivity, email, browsing and the like.Modern gaming isn't really on the menu, though. Our gaming and graphics benchmarks showed that even an older title like the decade old Tomb Raider was only playable at 720p with low image quality settings. The Ryzen Embedded R2000 Series' low power limit on the DFI PCSF51 and limited memory bandwidth hold it back in graphics-heavy workloads. If you want to game on the PCSF51, you should probably look to much older PC titles or dabble with some console emulators.
Some of the demanding benchmark scores looked anemic on this tiny 12W SBC. It is obviously not designed for power users, but rather makers and x86 SBC enthusiasts, and for industrial applications.
Our conclusion is colored strongly by the business-class industrial pricing of this SBC. The unit as tested is listed at $580, plus $28 for our preferred 'wide temp heatsink'. You also need to use an existing or source a new 12V 2A PSU. If priced at $299 or so, the DFI PCSF51 would have much wider appeal, but DFI hasn't been playing in the consumer space for years, as has been focused on large organizations and specialized industries.
Looking to the not-too-distant future, considering the DFI PCSF51's gen-over-gen improvements, we think that compact devices featuring one of the new Ryzen 7000 mobile chips would have a much greater gravitational pull on our typical readers. AMD's latest Ryzen 7040 "Phoenix" APUs for example offer the newest Zen and RDNA architectures, and we have seen that they can be quite performant, even in low wattage portables, like the Ayaneo 2S and ASUS ROG Ally. We aren't aware of any Phoenix SBCs currently in the works, but there are already a number of handhelds, mini PCs and laptop design wins for the APUs. Here's hoping they arrive on some affordable SBCs, because they'd be a great fit.
