Comment 9 for bug 1123108

Official support for Ubuntu 12.10 "Quantal Quetzal" and Ubuntu 13.04 "Raring Ringtail" has ended. If anyone is still experiencing this issue on Ubuntu 12.04 "Precise Pangolin" please check if this issue still exists on Ubuntu 14.04 "Trusty Tahr".

Trusty has a 3.13-based kernel which introduced proper AMD Radeon DPM (dynamic power management) for the first time. Further Radeon DPM improvements were made in subsequent kernels. In particular, kernel 3.17 re-enabled DPM for AMD "Cayman", "Barts", "Turks" and "Caicos" hardware after it was disabled in kernel 3.14 for stability reasons. This is first included in Ubuntu 15.04 "Vivid Vervet" which is based on the 3.19 kernel.

Anyone who still has this issue on Trusty (more likely for users with Intel or NVIDIA hardware due to the reasons I outlined above), please check that you are not running the fallback llvmpipe renderer by running this command in a terminal window:

glxinfo |grep renderer