5800X3D CPU0 100% usage at idol after upgrading to 6950XT

[Avernix4200]

Very strange/interesting problem I'm seeing here and searching the net has yielded nothing.

System Specs:
CPU: 5800x3d w/ H150i Elite Calipex Cooling
MOBO: Asus Crosshair Dark Hero VIII
RAM: 32GB 3600mhz c14 Trident Z Neo (4 sticks x 8GB)
Graphics Card: AMD Reference 6800xt upgrading to a brand new XFX 6950xt 319 Merc
PSU: EVGA 1300W G+ Supernova
NVME: 2TB Samsung 980 Pro + 1TB Samsung 980 Pro
SATA: x2 Samsung 500 series 500gb SSDs

The Problem:

When installing the new 6950xt, CPU0 gets pegged at 100% usage from time of boot even when completely idol and because of this performance tanks. Task manager and resource monitor show no processes on CPU0 to account for the high usage. When swapping back to my old 6800xt, CPU0 behaves as normal without issue.

The 6950xt does not seem to be damaged and appears to render 3d content as expected. Running 3dmark graphics tests where the GPU is working alone go fine, the second the CPU tests come is where we really see performance tank, getting about 10% of the usual performance i get from this CPU. This behavior also results in extreme stuttering and low overall FPS in game.

I have had a two total odd dark green screens when alt tabbing during testing the 6950xt, something the 6800xt never did. This could point the card being bad which is why I have already started RMA, but could also just the driver support because its such a new product.

Again none of this happens with the 6800xt installed. The system has been running fine for over a year, both with a 5800X and 5800X3D so I'm confident in my current components. To me this seems like BIOS shenanigans on either the XFX 6950XT part, or the Dark Hero VIII MOBO.

Things I tried but nothing worked:

Complete Driver reinstall multiple versions of CPU, GPU, even audio with windows auto driver update disabled. (note: problem persists even with no AMD CPU/GPU drivers installed, tried both with and without DDU and with and without AMD Clean up utility)
6950 XT is dual bios, so i tried both, neither helped
Ran sfc /scannnow, no errors to report
Complete Windows 10 Reinstall (reinstalled from local install, not from USB idk if that makes a difference.)
Updated from windows 10 to windows 11
MOBO BIOS update to current and rollback to multiple previous versions.
Remove and reseat 6950XT to ensure a good PCIE connection
Inspected 6950xt PCIE connection to ensure no damaged traces
Booted computer with only monitor, mouse, and keyboard connected to see if there was a peripheral that was interfering
Booted computer in safe mode to ensure no windows process or software was causing this issue

Playing around with various different BIOS settings. (Note: with 6950xt installed and when D.C.O.P is enabled, basically D.C.O.P is the equivalent of X.M.P. for you intel users, CPU0 usage is 100%, when disabling D.C.O.P, CPU0 usage is pegged at around 70% instead of 100%. This leads me to think it might me a motherboard compatibility issue and maybe ASUS needs to issue another BIOS update? But then why does it work just fine with the 6800XT?)

For now, I have downgraded to my 6800xt, ordered another 6950XT for science, and returned this XFX one. This time a Sapphire 6950xt Nitro + Pure. Will update post if this was just a bad GPU or something deeper to dive into. If you have suggestions, I still have the XFX card for now for troubleshooting, and can easily plug it in to test theories, it would be interesting if we could get it work.

I'm Posting here because I think I've narrowed it down to either the 6950xt maybe having a bad BIOS? Or possibly MOBO needs a BIOS update released? I have already reported this to AMD and ASUS but XFX website is horrendous for customer support.

As to the screen snips below, 2 show the 100% usage with the 6950XT installed, the 3rd is normal behavior after switching back to the 6800XT. It should be obvious which ones.

Thanks in advance for the help/advice.

[xeromist]

Since you already have a new card coming I'd wait for that. The green screens point to a GPU issue and you did just about everything I would think of to eliminate a driver issue. If it still happens with the new one then that's when it's time to get concerned.

[Avernix4200]

xeromist wrote:
Since you already have a new card coming I'd wait for that. The green screens point to a GPU issue and you did just about everything I would think of to eliminate a driver issue. If it still happens with the new one then that's when it's time to get concerned.

agreed, thats pretty much what ive decided to do. ill update post tomorrow when i get hands on with the new card. thanks

[Avernix4200]

Can confirm, the GPU itself was bad, I suspect a bad BIOS issue with it. The Sapphire Nitro + Pure card runs without issue, might avoid XFX in the future for now, the 2nd bad experience I've had with them in under 2 years.