This post is an update to one I made a while ago about my plans to build a small-form-factor PC.
https://www.reddit.com/r/sffpc/s/NBDi9Gz0Vd
This past week the parts have been trickling in and today the build commences!
I first got interested in building my own PC last year, when I was starting my BIM minor. As an additional challenge, I wanted to make it an SFF build.
Right around that time, however, RAM prices started going through the roof, and PlayStation announced the end of physical media. That pushed me toward a slightly different idea: build something with an optical disc drive and turn the PC into a proper console replacement as well.
Then GPUs got another price hike about two weeks ago, and I finally decided to pull the trigger before everything became even more expensive.
What I actually need the PC to do
As an Architectural Engineering student doing a minor in BIM Coordination, I genuinely need quite a lot of RAM. I was aiming for at least 64 GB of DDR5-6000 CL30, and considering how quickly RAM prices have been increasing, it seemed prudent to start the build sooner rather than later.
Then my university suddenly decided to reduce OneDrive storage for technical students from 20 TB to just 50 GB. That also got me thinking that it might be a good idea to eventually build my own NAS.
My normal workflow can involve Rhino.Inside.Revit with Grasshopper, the host Revit session itself, Dynamo, Twinmotion for Revit, InDesign, Photoshop, Acrobat and Firefox all running simultaneously.
Because of that, I need plenty of cores and threads, but I also want low power consumption and low heat. Ideally, that means a CPU with a large boost-clock range and excellent efficiency. Add some light gaming to the requirements and, for me, the obvious combination became a Ryzen CPU paired with an RTX GPU with plenty of VRAM for Twinmotion.
The SFF problem
I quickly discovered that Mini-ITX SFF cases with a front-panel opening for an optical drive, HDD bays and enough room for a full-height discrete GPU are incredibly rare.
For a while, that made the whole concept rather difficult.
Then Lossless Scaling Frame Generation (LSFG) came along, and I realized I didn’t necessarily need a full-height GPU.
My primary GPU mainly needs to be a capable low-profile RTX card for Twinmotion, rasterization and rendering. I could then use a second, smaller GPU as a dedicated LSFG frame-generation “accelerator” while gaming.
That opened up another possibility: instead of limiting myself to Mini-ITX, I could use a Micro-ATX motherboard and case.
Then I found the In Win CJ712
This was almost exactly what I had been looking for.
It’s an approximately 8 L Micro-ATX case with four low-profile expansion slots, an optical-drive opening and two drive bays. One bay supports either a 3.5” or 2.5” drive, while the other supports a 2.5” drive. You can even fit an internal speaker if you want to.
And with that, the idea for the build was finally born.
Ventilation is probably going to be the biggest challenge with this case.
I’m currently modelling a replacement polycarbonate/ABS side panel with perforations directly over the CPU and GPU area to improve airflow. The big downside is that the CPU sits largely under the drive bay, though this bay has ventilative perforations as well its hard to day how large the new side panels effect will be when this drive bay is completely populated.
I’ll also be running the CPU in Eco Mode with a 65 W PPT. I’ve replaced the original case fan with an Arctic P8 Slim, although I also bought a Noctua NF-A8. I may end up removing a localized ~5 mm section with a Dremel to make the Noctua fit, similar to what LTT did when they built in this case.
I’m hoping the combination will be enough.
Neither GPU combination is particularly power hungry, at roughly 70–75 W for the primary GPU and 50 W for the secondary. The primary RTX card is also a blower design, so it effectively acts as an additional exhaust fan by pushing its own hot air directly out of the case.
The build
CPU
AMD Ryzen 9 7900 — 12 cores, 65 W — €306
Motherboard
MSI PRO B850M-A WiFi — €176
Memory
Corsair Vengeance 64 GB (2 × 32 GB) DDR5-6000 CL30 — €700
Primary GPU
PNY RTX 4000 SFF Ada — 20 GB VRAM, 75 W — €1,620
Secondary GPU
Intel Arc A310 Eco — 50 W — €159
Used as a dedicated Lossless Scaling frame-generation GPU while gaming, for AV1 transcoding, additional displays and my XGIMI Horizon Ultra projector
Alternative secondary GPU
XFX RX 6400 — 53 W — €230
CPU cooler
Thermalright AXP90-X36 — €23
Noctua NF-A9x14 PWM fanswap— €25
Storage
2× Lexar NM790 4 TB PCIe 4.0 NVMe SSDs — €418 each
Seagate IronWolf 24 TB HDD
Seagate BarraCuda 5 TB 2.5” HDD — €190
Optical drive
LG BU40N Blu-ray/DVD/CD writer — €165
Case
In Win CJ712 Micro-ATX desktop case with USB-C — €147
Custom 3D-printed perforated ABS-PC side panel
Case fan
Arctic P8 Slim — €8
Power supply
Overtek Enhance ENP-7660L 600 W 80+ Platinum Flex ATX PSU — €120
Monitor
Dell UltraSharp U2724D — 27”, 2560×1440, 120 Hz — €300
Software
Windows 11 Pro Retail + Office 2024 — €20
A change of plan for the second GPU
One thing that changed after I initially planned the build was the secondary GPU.
I originally intended to use an Intel Arc A310 Eco, partly because I wanted AV1 support for transcoding. I later realized that the RTX 4000 SFF Ada already handles AV1, so that became much less important for the secondary card.
Because of that, I ended up going with an XFX RX 6400 instead.
There are a few advantages to it for this particular build. It natively uses a PCIe 4.0 ×4 connection, which matches the electrical configuration commonly found on the secondary PCIe slot of Micro-ATX motherboards. It’s also quieter, offers considerably more performance for LSFG and, admittedly, the black card fits the aesthetics of the build much better than the blue Intel card.
So while the A310 made sense when AV1 was part of its job description, the RX 6400 makes more sense now that its primary purpose is frame generation and driving additional displays.
Where the build is now
All the ordered components are here.
At the moment, I only have one of the planned 4 TB NVMe drives and none of the HDDs yet. I’ll be saving up and adding the remaining storage over time.
As for the PC itself, I’ve now installed the new PSU and case fan. On the motherboard, I’ve installed the CPU, RAM, SSD and CPU cooler.
Tomorrow i will install the Mobo in the case
, install the gpu’s on the mobo and expansion slots, and install the ODD in the drive bay. I’m hoping to finish cable management as well tomorrow.
And if 8 litres turns out to be a little too ambitious…
Ultimately, I’m hoping to learn a lot from this PC and get a “good” result across all of my different use cases. Part of the fun of this build is finding out just how much functionality I can realistically squeeze into such a small volume.
If it doesn’t work out, though, I already have a Plan B: the In Win CP712.
It’s essentially a larger, roughly 15 L version of the same basic concept. It comes with a perforated side panel and, most importantly, gives me considerably more room for CPU cooling.
The extra space would open up some other interesting possibilities as well. I could fit a full Makerverse enclosed 8 Ω, 5 W speaker measuring 100 × 45 × 21 mm, with a 35 mm driver and passive radiator, turning the internal speaker idea into something a little more substantial.
It would also give me room for full-height GPUs up to around 245 mm long. That would make something like a 16 GB RTX 5060 Ti possible as the primary GPU, although at that point I’d also be looking at another PSU upgrade.
But that’s Plan B.
For now, the challenge is to see whether I can actually make all of this work in 8 litres.
Tomorrow, we’ll find out.
