Gaming on Linux with a graphics card with 8GB or less of VRAM just got a bit easier, thanks to Valve developer Natalie Vock. She recently created fixes that ensure limited VRAM is prioritised for games, thereby improving performance, preventing stutters and generally making for a smoother gaming experience.
But why were these fixes required in the first place? In essence, the Linux kernel doesn’t differentiate between games and non-games out of the box when it comes to video memory requests, so in scenarios where that memory is full, a running game might be evicted from VRAM instead of a background task like Chrome, Discord or even Steam.
By running a combination of kernel patches and helper packages, your system is able to accurately identify running games and ensure they are only evicted or spill over from VRAM as a last resort. This is important because, as well as having much lower latency, VRAM has an order of magnitude more bandwidth available to transfer data – so being evicted from video memory quickly causes problems.
By having this prioritisation in place, your available VRAM can effectively grow by hundreds of megabytes – or even a few full gigabytes – which is massive on a system with only two, four, six or eight gigabytes in total. You still need to keep an eye on a game’s VRAM usage, as exceeding what’s physically available still causes performance issues, but this optimisation is still well worth activating.
In order to benefit from the new fixes, the easiest way is to be running the CachyOS Linux distribution with the default KDE Plasma user interface. Then, you just need to install two new packages called dmemcg-booster and plasma-foreground-booster. You can also get the packages from AUR on any Arch Linux install, though you’ll need to perform your own kernel patches or use the CachyOS kernel instead – a bit trickier. The kernel patches ought to come to more distributions in the future.
Both AMD and Intel graphics cards ought to benefit, but Nvidia’s proprietary drivers are unfortunately a no-go for now. Note that integrated graphics don’t really have the same issues with paging out to system RAM, so the fixes here shouldn’t affect performance in any meaningful way and you don’t need to install them.
If you’re interested in Natalie’s fascinating full explanation of the issue, and how she developed a solution working with Intel’s Maarten Lankhorst and Red Hat Linux’s Maxime Ripard, you should read her blog post on the subject.
