I built my own Steam Machine. It was way easier than I expected
What I had available
One of the perks of writing about and working with PCs and hardware is that I typically have a few bits lying around. In this case, I repurposed my old VR gaming PC, the one that steadfastly kept my HTC Vive Pro going even in 2024 but has since been boxed up and idle.
Why let that go to waste? I decided it would be a fine candidate for repurposing into a Steam Machine. Its hardware is ideal for the job:
- CPU: AMD Ryzen 7 3700X
- Motherboard: Asus ROG X670E Crosshair Hero mini-ITX
- Memory: 16GB Corsair Vengeance 3000 MT/s DDR4
- Storage: 512GB Samsung 980
- Graphics: PowerColor Red Devil RX 7900 XT 20GB
- PSU: Corsair SF850 SFX 850W
The CPU is older than the custom processor Valve uses in the real Steam Machine, with a lower boost clock at 500 MHz and only support for slower DDR4 memory. That means it lacks some of the more modern advances of the Steam Machine’s custom Zen 4 chip, but at least it packs two extra cores, support for four more threads, and double the cache. With its TDP being over 4x higher, I’ll be needing a more capable cooling solution than Valve’s smart heatsink and fan combo.
As far as memory, it has equivalent capacity at 16GB, but it’s DDR4 so it’ll be slower (even with the XMP/EXPO profile enabled).
The real kicker here is the GPU. The RX 7900 XT is still one of the fastest graphics cards AMD has ever made, beating out more modern counterparts like the RX 9700 (non-XT). It should be roughly 2.5x the performance of the graphics chip in the official Steam Machine, giving us much greater scope for reaching that 4K/60Hz threshold Valve originally targeted with its little box. My system also has boatloads of VRAM at 20GB—even more than modern cards like the RTX 5080 and RX 9070 XT—so it won’t run into VRAM bottlenecks anytime soon.
My plan was to build all this into a Corsair 2000D case that’s been gathering dust in the corner of my office for the past couple of years, and I’d keep the CPU chilled with a Cougar 240mm AIO that’s seen better days but seems to still work well enough.
All that said, this is massively overpowered for what a DIY Steam Machine needs to be. Any quad-core-or-better CPU from the past five years should suffice, and you can probably get away with 8GB of RAM if that’s all you have. You don’t need much for the GPU, either. Remember, Valve is working with a mobile RX 7600 equivalent, so to get decent 1080p performance with SteamOS, you can get by with almost any GPU from the past few generations to be competitive. (For ideas, see my colleague’s DIY Steam Machine build for $150 less than MSRP.)
