The versions of the drivers in SteamOS are well behind up to date stable, let alone testing. You can easily pull in one of the many PPAs that track the latest s

The versions of the drivers in SteamOS are well behind up to date stable, let alone testing. You can easily pull in one of the many PPAs that track the latest stable and/or testing kernel/MESA/DRM/DRI stacks (such as xorg-edgers, obiaf or others). If you are not happy with what is provided by stock SteamOS then your issue is with Valve's distribution not the current state of the drivers.