This is a translation of a foreign article, so there may be translation errors.
https://hothardware.com/news/valves-vram-hack-could-save-millions-of-8gb-gpu-owners-from-stutters
Valve's VRAM Hack Saves Millions of 8GB GPU Users from Stuttering
Valve engineer Natalie Vock has discovered a GPU memory optimization method for Linux that significantly improves the memory handling capabilities of AMD GPUs. While it's unclear how this advantage will be applied to the upcoming 'Valve Steam Machine' using AMD iGPU, memory optimization is always welcome news in the current market situation.
Natalie explains, "Enduring stuttering and slowdowns that occur when the system's available VRAM begins to run low requires tremendous patience and determination. When all applications fight to occupy as much GPU memory as possible, chaos ensues inside the kernel driver. Games caught in this resource war inevitably suffer. But now I've solved that problem."
Before optimization, a significant portion of the AMD GPU's 8GB VRAM was allocated to other applications, interfering with Cyberpunk 2077 execution.
Before applying the fix, Natalie conducted tests by opening multiple applications on Linux and then running Cyberpunk 2077 on top of them. She did not reveal which specific AMD discrete GPU was used, but it is likely the 8GB Radeon RX 9060 XT. Regardless of which GPU was used, Cyberpunk was not properly allocated video memory, with only 6105 MiB of 8176 MiB of VRAM allocated to the game thread. To make matters worse, due to Linux's GPU memory allocation handling method, the aforementioned stuttering and slowdown were prone to occurring.
After creating and applying a kernel patch to reduce the slowdown caused by resources moving between system memory and VRAM for the currently running game, Natalie confirmed significant improvements in both the playability of Cyberpunk 2077 and actual VRAM utilization. While overall VRAM usage on the card decreased, the actual VRAM usage by the game increased, and background processes no longer consumed much video memory. Additionally, GTT usage, the system RAM area accessible to the GPU, was also significantly reduced.
After optimization, Cyberpunk 2077 was able to use over 1000 MiB of additional VRAM.
This is a significant amount of additional memory available to the GPU. However, since there are no benchmark results, the exact FPS improvement figures are unknown. At the very least, reduced data transfers to system memory should result in more consistent frame times. Unfortunately, NVIDIA's closed-source GPU driver cannot benefit from this patch unless it adds dmem cgroups support, but Intel GPUs using the Xe kernel driver may benefit from it.
▶ Original Source: https://hothardware.com/news/valves-vram-hack-could-save-millions-of-8gb-gpu-owners-from-stutters
