Pcie Problems

2021-03-13

Just a quick heads up to anyone building a new PC with one of the new gen GPUs (Ampere or Big Navi). This will mostly affect those of us with SFF cases, but if you’ve gone for a vertical mount on your GPU you may be affected too.

Riser cards/cables are PCIe 3.0. New motherboards and GPUs are PCIe 4.0. If you leave the PCIe detection to auto the risers will just pass through whatever is fed to them and you can end up running PCIe 4.0 signal over PCIe 3.0 hardware and this can be problematic. Often it will fail to post, however as I learnt from the very fortunately timed Hardware Canucks video that isn’t always the case. Sometimes they will post fine but then suffer bluescreens and so on.

My crash was particularly weird - after an indeterminate time playing a game (but usually <15m) the game would freeze - either with a black screen or the last frame rendered. Sound would continue and the OS was unaffected so I could tab out, kill the game and start again. Only one game gave me any kind of error message which was Generation Zero and it said: dxgi_error_device_hung and then something about updating graphics drivers and so on.

This led me down a bit of a wild goose chase but I was able to confirm it wasn’t a driver issue. The only change from my old 980, really, was the PCIe version so after seeing that video I went in to the BIOS and manually set it to PCIe 3.0. I have not had a single crash since. I’ve dropped about 500 points in Superposition so there is some performance penalty but well worth it for now until PCIe 4.0 risers are less expensive and more available.

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