GPU not functioning in top 16x port on many motherboards...
GPU not functioning in top 16x port on many motherboards...
Hey all, buckle up cause I've got a weird one. I picked up a used MSI Gaming X RX 470 4gb from a buddy's mining farm for cheap because he said it doesn't work. I have tinkered with it for a bit and discovered that it will only work in PCIe 8x or smaller slots. I re-flashed the bios (although I believe it was unchanged. I have tried the following on the following 3 motherboards: Mobo 1: Z390 Phantom Gaming 4s/ac w/ 9700kf: Works in the second slot (wired for 4x) no problem. Does not work in top slot (wired for 16x) with or without taping off the connector. My test GPU (quadro k4000) and a spare 1070ti I have both work in the top slot (as well as countless other cards as this is my typical test system). Mobo 2: GA-Z87X-D3H w/ 4590(I think lol): Works in the second slot (wired for 8x) no problem. Works in the top slot IF I tape off the PCIe connector on the card down to 8x or 4x (GPU-Z reports it running at the respective bandwidth). Does not work in the top slot if I do not tape of the slot. Quadro or 1070ti works in any slot. Mobo 3: X99 Extreme4 w/ 5820k: Works in the bottom slot (wired up for 8x). Does not work in any other slot with or without tape. Other cards work fine. I am lost. I have a feeling that there is any issue with the PCIe controller or traces on the PCB (I don't see any damage but I am not very well versed in PCB repair). But if that was the case then theoretically taping off the slot would tell the motherboard to just run the card at 8x/4x as to the motherboard I am only plugging in an 8x/4x device. Has anyone seen behavior like this before and have any suggestions for fixes? Really appreciate any and all help!