VaanaCZ/LANVP

force_borderless_window=0 causes high GPU utilization compared to force_borderless_window=1

eXhumer opened this issue · 2 comments

Using force_borderless_window=0 causes high GPU utilization compared to force_borderless_window=1.

I have a 1080 Ti and usually play games in 1440p60FPS while I use a 4K monitor. For this reason, I wanted to set force_borderless_window=0 to make the window fill the screen. What I found weird was that the GPU utilization skyrocketed to ~80% according to RTSS from ~30% in windowed mode in 1440p60FPS. I can play 4K60FPS with force_borderless_window=1 with ~50% utilization while, setting it to 0 increases the utilization to 60% while forcing the FPS to drop to 30 (possibly due to lack of GPU headroom).

Why is force_borderless_window=0 causing this unusual increase in GPU utilization?

I have not looked into it yet, however I do have a few notes regarding the issue.

Using force_borderless_window=0 causes high GPU utilization compared to force_borderless_window=1.

That sounds normal.
When running in a (borderless) window [force_borderless_window=1], the game is, simply put, treated as just another application, meaning utilization is limited, since it has to share resources with other applications that are currently utilizing the GPU.
However, when in fullscreen mode [force_borderless_window=0], the game runs in "exclusive" mode, meaning it's given full control over the GPU, with all it's resources, while everything else is pushed to the back.
So in short, your GPU utilization does increase when you switch to fullscreen, that's intended behaviour of the driver.

I can play 4K60FPS with force_borderless_window=1 with ~50% utilization while, setting it to 0 increases the utilization to 60% while forcing the FPS to drop to 30 (possibly due to lack of GPU headroom).

This part is weird. I can think of one possible cause, and that is image scaling. However, that should definitely not stress an 1080 Ti that much, so it's hard to imagine that is the case.

In that case, it's probably an issue with L.A. Noire's renderer implementation. It's something definitely worth looking into, although I am not sure how much will I be able to help.

In the meantime, could you try running the game DX9 mode and see if the same issue happens? That might help narrow the issue down a bit to see what causes it.

To do so, you need to set force_dx11 to 0 in lanvp.ini

;
; Enforces DirectX 11 mode for better performance.
; Only enabled if the users PC has a Direct3D 11
; capable graphics card.
;
; 1 = enabled
; 0 = disabled
force_dx11=0

And then make sure that your Renderer is set to DirectX 9 in settings.ini (Your User Folder\Documents\Rockstar Games\L.A. Noire)

Renderer:DirectX 9

Thanks for the reply. I tested it with force_dx11=0 and it looks like it fixed the problem. I am seeing similar FPS/GPU utilization numbers that I saw in windowed mode at the same resolutions (1440p/4K). So, it looks like DX11 related issue.