Drivers & Software

[murkar]

Wondering if anyone else is experiencing issues with the 6700XT on Nanite Foliage that causes extreme flickering on meshes and shadows in the latest version of Unreal Engine?

Bug id demo'd here but sad to find this since there are no issues with NVIDIA cards; took a chance on AMD this cycle but if this is a driver issue or something that's just being left, it doesn't leave much choice but to avoid AMD for production work in the future. Tested and confirmed across two different 6700XTs and confirmed that it does not happen on RTX 4090, RTX 2070, or even on GTX 1070.

https://www.youtube.com/watch?v=sD4g6V4tPFY&feature=youtu.be

[PreyK]

Same here.

RX 7900XT

23.1.1

No solution yet. Wanted to try Vulkan instead of DX12 SM6 but the engine just crashes for me when switching to it.
Not sure if it's a 7000 series problem, a general AMD one, or an Unreal one.

[murkar]

Hey there -

Thanks for the update, glad I'm not the only one experiencing this problem and that it's definitely an issue with AMD drivers or the engine. I reported it to UE and they did not confirm it as a bug; I think it's an AMD driver issue because I have not been able to replicate it on any NVIDIA hardware (now tried on 3 different cards from 10 series to 40 series and no issues at all).

I was hoping the new drivers would fix this but if it's an issue on the 7000 series then it's obviously not been fixed. Shame to see it on their newest hardware but not great that it's happening on anything.

Did you use the AMD reporting tool to submit an issue report? Probably the more confirmation they get, the faster they'll look into resolving it.

[PreyK]

Same here, good to know I’m not the only one.

Seems to be a driver problem, I’ve also collected some more problems with unreal and submitted it to the developer forum because it’s monitored by mods I’m hoping someone will pick up on it faster.
https://community.amd.com/t5/newcomers-start-here/serious-issues-in-unreal-engine-on-rx-7900xt/m-p/5...

I’ve also done some more digging and it looks like hardware raytracing has been broken since at least December:
https://forums.unrealengine.com/t/what-is-the-setting-for-unreal-engine-5-1-with-amd-radeon-gpu-rx69...

I’ve submitted a bug report with the AMD bug report tool for the vulkan crash because that’s clearly an AMD bug.

My theory is that no matter how bas DX12 SM6.6 is, vulkan in theory should just work for Nanite stuff because amd supports VK_KHR_shader_atomic_int64 so getting vulkan to function would be at least a partial solution until they figure out DX12.

But honestly seeing hwrt being broken for a while I wouldn’t be too optimistic.

I also couldn’t reproduce anything on that list on Nvidia and it’s just soo frustrating.