Map/unmap causing persistent frame stutters, what do I do?

Here is a picture of a 30 second recording from Black Ops Cold War Imgur: The magic of the Internet

I’m pretty sure it shouldn’t look like this, and while in game I’m constantly stuttering in tiny tiny time increments but its so frequent that it renders the game unplayable. Any advice? All of the stutters say around the following:

“Map / unmap accumulated time in frame
Begins: 0.627103s
Ends: 0.650452s (+23.349 ms)
Accumulated time 0.70ms for 532 function calls is 782.70% greater than 0.08 which is the median duration of the surrounding 19 frames:
2 calls: ID3D12CommandQueue::UpdateTileMappings
265 calls: ID3D12Resource::Map
265 calls: ID3D12Resource::Unmap”

Hi cookecaius,

Nsight Systems is providing hints about the cause of the stutter by comparing the cumulative time spent in a particulare type of functions (e.g. map/unmap function calls) in a frame to the respective time spent in that type of functions in the surrounding frames.

I see you have a separate queue for copy operations. The screenshot you provided is zoomed-out so I can’t see the details inside the stutter frames. I suggest you look at concurrency of command lists submitted to the graphics and copy queues, and try to reduce synchronization between them so copy ops are performed asynchronously to the graphics command lists, as much as possible.

If you can upload the Nsight Systems report file (QDREP suffix) I could try to dig deeper.

Doron

The QDREP fails to upload every time I try. Where else should I go?

In terms of getting you that file^

You can email the file to devtools-support@nvidia.com. Put a reference to the forum post in the email and I’ll follow up on it.

Doron