Question RTX 4080 sometimes not detected - I've tried everything

[aurb99]

So I built this PC a few weeks ago, and I'm having a consistent issue where the GPU is sometimes not being detected, forcing me to use the iGPU instead. The issue usually only happens when I restart the PC. If I shut it down at the end of the day and leave it off overnight, it will normally boot up with no issues in the morning.
When the GPU isn't detected, if I run a monitor from the iGPU and go into Windows, the 4080 will only show up under hidden devices in the device manager.
The GPU's fans and lights are running even when it's not being detected.
When the GPU is being detected, it works perfectly. I'm running the most demanding games at the highest settings, path tracing etc, and absolutely no issues whatsoever. Temps are usually between 60-70 when running these games.

I have literally tried everything you can think of -

- fresh Windows 11 install
- updated bios to latest version (2.08)
- GPU drivers are up to date
- DDU reinstall of drivers
- updated AMD chipset drivers
- reseated the GPU numerous times
- reseated RAM
- tried without additional SSD and HDD connected
- cleaned PCI connectors
- cleared CMOS multiple times
- tried with both display port and HDMI
- ran CMD prompt as administrator, and ran "bcdedit /set pciexpress forcedisable"
- ensured that external GPU is set as priority in bios
- disable fast boot in bios
- tried GPU in different PC, works without any issues

There's probably other things that I've tried which I'm not remembering at the moment, but I'm completely out of ideas now.

Does anyone have any other potential solutions that I can look at? I'd prefer not to replace the motherboard or CPU if possible.

Specs -

Palit RTX 4080
7800x3d
ASRock B650e Taichi
32gb Corsair Vengence RAM
RM1000x PSU
Dark Rock Pro 4

 

[alceryes]

You've already done a lot of diagnosing. I think it's time to try another GPU in your system.

Oh, something to check, some PSU's PCIe aux power cables are unidirectional. You must have the end labeled GPU plugged into your GPU or all sorts of weirdness can happen. Both ends should be labeled.

Good luck!

 

[aurb99]

You've already done a lot of diagnosing. I think it's time to try another GPU in your system.

Oh, something to check, some PSU's PCIe aux power cables are unidirectional. You must have the end labeled GPU plugged into your GPU or all sorts of weirdness can happen. Both ends should be labeled.

Good luck!

Thanks, the cables are defintely connected the right way. I don't have another GPU to test unfortunately, looks like I might just have to try another motherboard