Arch Linux

Nosrep

Member

Registered: 2021-05-15

Posts: 4

Terrible performance in 5.18 with an AMD card

On the 5.18.1 kernel I get really bad performance with my R9 280x. In Minecraft (with shaders), TF2, and glxgears, I get a third of the fps previously. I've enabled Southern Islands support in GRUB (and lspci also shows amdgpu, not radeon). I've downgraded back to 5.17.9 and all the issues are resolved. Any idea what could be causing this?

Last edited by Nosrep (2022-06-07 01:48:24)

Nosrep

Member

Registered: 2021-05-15

Posts: 4

Re: Terrible performance in 5.18 with an AMD card

Well, the latest git version of linux works too, but in 5.18 the problem's disappeared too, and I don't know what caused it.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,208

Re: Terrible performance in 5.18 with an AMD card

It's quite likely that you got some initial stuttering due to a mesa update (... or an actual bug there)). Whenever mesa updates (or at least the major version, i.e. 22.0 -> 22.1) all caches for shaders and the like you had need to be rebuilt. So you likely saw stuttering during initial generation, surmised something was wrong, rebooted into 5.17.9 which could use the generated shaders, where everything was fine, and then noticed it wasn't actually an issue in the kernel or in fact an issue at all.

You can generally expect stuff to stutter and relevantly fix itself on mesa updates due to shaders getting recompiled/recached

Nosrep

Member

Registered: 2021-05-15

Posts: 4

Re: Terrible performance in 5.18 with an AMD card

aight, thanks