Minisforum UM790 Pro, 64gb, 2x PCI-e Gen4 M.2 slots (one occupied by a 4tb drive)
Mounted as shown here:
PSU: Evga 850 GM
OS: Windows 10
All of this ran in my old PC (Ryxen 9 5900x, 32GB of 3600MHz RAM, same 3080 XC3 Ultra, same power supply) without issue but I wanted something that used less power overall until I wanted it to use more for things like gaming or encoding. The Ryzen 9 5900x is a hog when it comes to power consumption.
Anyway, with this same setup I can get my old 2070 to be recognized no problem. I can't get the 30-series cards to do anything. I add power, they spin up for a moment, then nothing. No display, and Windows won't recognize it. I think it's because it's on PCI-e 3.0 but I can't guarantee it. I swapped the 3080 to another computer in the house and pulled its 3070 to try and the 3080 works in the other system but it won't work here. I tried different power cables, but I doubted that was the problem because the same setup ran in my PC without issue and I'm not getting the red lights next to the power plugs which normally tell you if you don't have power.
I heard that AMD cards tend to do better with this kind of setup but if that's the case I want to be certain that I'm getting the right card for the job. My 2070 is doing about as well as the built-in 780M chip. I did put the 3080 into a Razer Core X but the mini pc only has USB 4 and not Thunderbolt so it spawned all kinds of errors at a rate of 20-40 per second and would bluescreen from time to time in the middle of gaming.
Thanks in advance for any help you can offer.