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GPUOpen-LibrariesAndSDKs / Capsaicin

AMD ARR team rendering framework
MIT License
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About the `ssgi_unroll_kernel_` option in scene viewer #3

Open Calinou opened 1 year ago

Calinou commented 1 year ago

I noticed there's a ssgi_unroll_kernel_ option in the Render Options panel at the bottom of the scene viewer GUI:

image

This option is disabled by default, but enabling it improves performance on a GeForce RTX 4090:

SSGI type 1920x1080 3840x2160
Unroll disabled 596 FPS (1.68 mspf)[^1] 175 FPS (5.71 mspf)
Unroll enabled 613 FPS (1.63 mspf)[^1] 181 FPS (5.53 mspf)

[^1]: Measured with V-Sync forcibly disabled in NVIDIA Control Panel, as the low GPU utilization causes the GPU to downclock (which makes the FPS estimation incorrect). Otherwise, I only get 300 FPS in 1080p on a 120 Hz display with V-Sync enabled.

Is there a reason it's not enabled by default? I can't spot any visual difference in quality, both in still scenes and when moving the camera.

gboisse commented 1 year ago

Thanks for reporting. We found this option to be slightly slower on our HW, but it does indeed calculate the same result.

Calinou commented 1 year ago

Thanks for reporting. We found this option to be slightly slower on our HW, but it does indeed calculate the same result.

I've tested this option on a Radeon RX 6900 XT and can confirm it makes no noticeable performance difference, so that makes sense.