Small PC, Big Performance
I've been building my own computers since 2001, but until recently they were all huge and heavy, with a mess of cables randomly scattered inside. I had always assumed that high performance components needed a lot of space, just check out my last build (2015) inside a 62 liter Antec P183 case, but then I discovered the wonderful world of small form factor (SFF) PCs.
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With mechanical and optical spinning disks no longer necessary, some things have improved in the SFF arena. However, with CPU and GPUs requiring more power and cooling, it's not quite as simple as you might think. Although thin and light laptops are pretty powerful today, and it's possible to get a USB stick sized Windows PC, the real challenge is cramming as much power into as small of a volume as possible.
SFF Chassis (Case)
The most important aspect with SFF is the case itself. It will dictate much of your component choice, orientation and level of complexity. My choice was the NCase M1. A standard layout, sub-13 litre case that started life on Indigogo in 2013. Manufactured by Lian Li in small batches, it's a rather expensive option, but it's extremely well-thought-out and well refined (version 6.1). It's not the smallest case that can fit high-end components, but it's where things start to get tricky and thus seems like a good sweet spot for many people starting out with SFF, even now.
UPDATE: Me from 2024 here. Now that this M1 v6.1 has been discontinued for a couple of years, NCase have finally come out with a new model (M2) as well as a refresh of this one (M1 Evo). The former to combat the ever-growing GPU sizes. I'm not planning on upgrading this machine any time soon, but I do love building PCs, especially SFF now, so maybe I will be tempted to do another build one day. The inescapable truth is that most of my time is spent on the laptop these days, so I will probably spend my money there instead.
With the panels on the M1 is pretty but fairly low profile, so I made this image to show some of the interior with the exterior. If the price of the Ncase makes you cringe check out the Coolermaster NR200. It's an NCase inspired design, but mass produced and thus considerably cheaper. At 18 liters it's about 50% bigger than the M1, but that makes it easier to build in and more forgiving with system components.
Compatability
Component compatability is perhaps the hardest aspect of SFF PC building so the best advise I can give is to do a ton of research before you buy, hopefully someone else has done something similar to what you want already and that can give you a huge advantage when choosing what GPU and cooling solutions are achievable in the case you would like.
My biggest issues with this build were: The uniquely shaped mini-DTX motherboard (Asus X570 ROG Crosshair VIII Impact), which is much lower than a standard mini-ITX and the fans I wanted to use at the bottom of the case (used for the deshrouded GPU). When plugging in the system cable (connecting to the cases power switch), shown above, it was extremely lucky that it fitted between the two 140mm fans. Note that there is no rubber padding on the fan corners, this is because there was only just enough room under this unusually low motherboard.
As you can see from the top down view of the NCase M1, there's a lot packed in here. Even with a deshrouded GPU it can be safely used with only 3 fans, tucked away from view. It will get hotter, but it's doable. If you want it to be as cool as possible you can fit another three. Maximising standard capacity of six fans, means two full size 140x25mm (for the GPU), two a 120x15mm (side), one 92x25mm (back) and one 120x30mm (CPU cooler). All this in a sub-13L case is pretty spectacular. This configuration also allows the SFX power supply in its default location on the side, where it can get fresh cool air. This is especially useful during low to mid use since the Corsair SF750 fan doesn't even spin until it draws 300w, so this way it can be much more safely passively cooled.
Compared to the initial build I switched the graphics card, RAM, fans, case panels (black), power cables and added two RGB LED strips. Here are the specification for the above build:
Case:
MB:
CPU:
GPU:
RAM:
PSU:
SSD:
Cooler:
Fans:
OS:
Sound:
Monitor:
NCase M1 v6.1 (12.7 Litre)
Asus ROG X570 Crosshair VIII Impact
AMD Ryzen 7 5800x (8x 4.8GHz)
MSI Ventus 3x RTX 3080Ti (12Gb GDDR6x)
G.Skill 32Gb Trident Neo (3600MHz cl14)
Corsair SF750
500GB WD SN850 PCI-E 4 (OS)
4TB PNY XLR8 CS3040 PCI-E 4 (Games)
4TB Samsung QVO 870 SATA (Photos)
Noctua NH-C14S (NF-A12x25)
2x Noctua NF-A14 (for GPU)
Win 10 Pro
Sony UDC-1
Acer XB321HK 32" 4k (IPS / G-Sync)
The biggest concern about this layout is that it can get hot and could add a few more fans to this side, so let me share some temperatures for the above configuration:
IDLE (after gaming):
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CPU temp/fan: 43°c / 864rpm (One 120x25mm)
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GPU temp/fan: 37°c / 643rpm (Two 140x25mm)
Gaming (Dirt Rally 2 @ 4k / 60 / Ultra settings for 30m):
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CPU temp/fan: 56°c / 1,225rpm (One 120x25mm)
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GPU temp/fan: 74°c / 1,026rpm (Two 140x25mm)
The fan behind the CPU cooler here was the Noctua NF-A12x25 set to exhaust. Rotating that CPU cooler fan back to intake, adding an NF-A9 on the rear (92mm intake) and two NF-A12x15 fans at the side (intake / exhaust) brings the CPU/GPU temperatures down by around 3°c at idle and 6°c while gaming. Whether this is worth covering the look of those lovely heatsink fins and bumping the noise levels (since all the extra fans are either small or thin) is debatable.
Custom 3D Printing
To get more of that great airflow from the two bottom 140mm Noctua NF-A14 fans on to the relatively thin GPU heatsink I turned to 3D printing. I had always wanted a 3D printer, but this finally pushed me over the edge into getting one. After a few small test prints and couple failed prints I finally got a good shape that funells all the air directly the to GPU and even holds the LED light strip.
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The under side of the front left and back right shrouds. Printed successfully by supporting each other with little bridge connections that could be easily cut later (to stop wobbling during the later stages of the print). You can see on this 3D view how much bigger the 140mm fans are than the Ventus 3x heat sink is and how easy it would be to lose most of the air around the sides, if not for the shrouds. This enables low spinning fans to get a huge amount over the fins.
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Below you can see the final shrouds, printed in black to match the black version of the case and the all black Noctua fan set.
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Here is the final mini PC in my work from home, workstation setup...
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This is my desk in November 2024. Three years on, I have removed the side fans from the PC now as having it all open is mostly fine, and it's nicer to see the internals. I now need to do some tidying of the cables a bit more, and it will be complete. Click here for more images of my bedroom workstation setup over my many years in the video game industry...
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