I’m getting similar issues in Preview 4 with some variation of DXGI_DEVICE_REMOVED/DXGI_DEVICE_HUNG on my 6800XT trying to use GPULM or the Path Tracer on its own. 21.6.1 drivers.
Path Tracer crash #1
[2021.08.07-00.50.56:949][183]LogD3D12RHI: Creating RTPSO with 135 shaders (134 cached, 1 new) took 3112.92 ms. Compile time 3097.21 ms, link time 15.62 ms.
[2021.08.07-00.50.57:037][183]LogD3D12RHI: Error: RetCode = Adapter->CreateCommittedResource(Desc, GetGPUMask(), HeapProps, InitialState, ClearValue, &NewResource, Name, false) failed
at D:/Build/++UE4/Sync/Engine/Source/Runtime/D3D12RHI/Private/D3D12Allocation.cpp:1381
with error DXGI_ERROR_DEVICE_REMOVED
[2021.08.07-00.50.57:037][183]LogD3D12RHI: Error: [GPUBreadCrumb] Last tracked GPU operations:
[2021.08.07-00.50.57:037][183]LogD3D12RHI: Error: [GPUBreadCrumb] 3D Queue 0 - Begin: Frame 1182 - Scene - Path Tracing - Path Tracer Display (1613 x 814)
[2021.08.07-00.50.57:037][183]LogD3D12RHI: Error: [GPUBreadCrumb] Compute Queue 0 - Begin: ClearTranslucencyLightingVolumeCompute 64
[2021.08.07-00.50.57:037][183]LogD3D12RHI: Error: [GPUBreadCrumb] Copy Queue 0 - No Data
[2021.08.07-00.50.57:037][183]LogD3D12RHI: Error: DRED: No PageFault data.
[2021.08.07-00.51.05:639][183]LogWindows: Error: Error reentered: Fatal error: [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/D3D12RHI/Private/D3D12Util.cpp] [Line: 684]
RetCode = Adapter->CreateCommittedResource(Desc, GetGPUMask(), HeapProps, InitialState, ClearValue, &NewResource, Name, false) failed
at D:/Build/++UE4/Sync/Engine/Source/Runtime/D3D12RHI/Private/D3D12Allocation.cpp:1381
with error DXGI_ERROR_DEVICE_REMOVED
[2021.08.07-00.51.06:782][183]LogWindows: FPlatformMisc::RequestExit(0)
Path Tracer crash #2
[2021.08.07-00.53.10:832][751]LogD3D12RHI: Creating RTPSO with 135 shaders (134 cached, 1 new) took 3117.20 ms. Compile time 3101.15 ms, link time 15.96 ms.
[2021.08.07-00.53.10:962][752]LogD3D12RHI: Error: pResource->Map(Subresource, pReadRange, reinterpret_cast<void**>(&pData)) failed
at D:\Build\++UE4\Sync\Engine\Source\Runtime\D3D12RHI\Private\D3D12RHIPrivate.h:1172
with error DXGI_ERROR_DEVICE_REMOVED with Reason: DXGI_ERROR_DEVICE_HUNG
[2021.08.07-00.53.10:962][752]LogD3D12RHI: Error: [GPUBreadCrumb] Last tracked GPU operations:
[2021.08.07-00.53.10:962][752]LogD3D12RHI: Error: [GPUBreadCrumb] 3D Queue 0 - Begin: Frame 751 - Scene - PostProcessing - EnqueueCopy(EyeAdaptation)
[2021.08.07-00.53.10:962][752]LogD3D12RHI: Error: [GPUBreadCrumb] Compute Queue 0 - Begin: ClearTranslucencyLightingVolumeCompute 64
[2021.08.07-00.53.10:962][752]LogD3D12RHI: Error: [GPUBreadCrumb] Copy Queue 0 - No Data
[2021.08.07-00.53.10:962][752]LogD3D12RHI: Error: DRED: No PageFault data.
[2021.08.07-00.53.10:964][753]LogD3D12RHI: Error: pResource->Map(Subresource, pReadRange, reinterpret_cast<void**>(&pData)) failed
at D:\Build\++UE4\Sync\Engine\Source\Runtime\D3D12RHI\Private\D3D12RHIPrivate.h:1172
with error DXGI_ERROR_DEVICE_REMOVED with Reason: DXGI_ERROR_DEVICE_HUNG
[2021.08.07-00.53.12:221][754]LogWindows: Error: Error reentered: Fatal error: [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/D3D12RHI/Private/D3D12Util.cpp] [Line: 684]
pResource->Map(Subresource, pReadRange, reinterpret_cast<void**>(&pData)) failed
at D:\Build\++UE4\Sync\Engine\Source\Runtime\D3D12RHI\Private\D3D12RHIPrivate.h:1172
with error DXGI_ERROR_DEVICE_REMOVED with Reason: DXGI_ERROR_DEVICE_HUNG
[2021.08.07-00.53.13:333][754]LogWindows: FPlatformMisc::RequestExit(0)
GPULM Crash
[2021.08.07-00.55.32:150][833]LogGPULightmass: Resizing GPULightmass scratch tile pool to (6, 6) 408x408
[2021.08.07-00.55.32:514][833]LogD3D12RHI: Error: hr failed
at D:/Build/++UE4/Sync/Engine/Source/Runtime/D3D12RHI/Private/D3D12Resources.cpp:477
with error DXGI_ERROR_DEVICE_REMOVED with Reason: DXGI_ERROR_DEVICE_HUNG
[2021.08.07-00.55.32:514][833]LogD3D12RHI: Error: [GPUBreadCrumb] Last tracked GPU operations:
[2021.08.07-00.55.32:514][833]LogD3D12RHI: Error: [GPUBreadCrumb] 3D Queue 0 - End: Frame 831 - SlateUI Title = PTTest - Unreal Editor
[2021.08.07-00.55.32:514][833]LogD3D12RHI: Error: [GPUBreadCrumb] Compute Queue 0 - Begin: ClearTranslucencyLightingVolumeCompute 64
[2021.08.07-00.55.32:514][833]LogD3D12RHI: Error: [GPUBreadCrumb] Copy Queue 0 - No Data
[2021.08.07-00.55.32:514][833]LogD3D12RHI: Error: DRED: No PageFault data.
[2021.08.07-00.55.37:703][833]LogWindows: Error: Error reentered: Fatal error: [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/D3D12RHI/Private/D3D12Util.cpp] [Line: 684]
hr failed
at D:/Build/++UE4/Sync/Engine/Source/Runtime/D3D12RHI/Private/D3D12Resources.cpp:477
with error DXGI_ERROR_DEVICE_REMOVED with Reason: DXGI_ERROR_DEVICE_HUNG
[2021.08.07-00.55.38:789][833]LogWindows: FPlatformMisc::RequestExit(0)