AMD OverDrive On Linux
With this OverDrive Linux support, users are also now able to monitor their GPU temperature, which previously wasn't supported by any utility and recently could only be exposed using pplib-cmd hacking. On the newer ATI GPUs it's also possible to read the GPU load percentage using OverDrive. To read the temperature of the GPU, run aticonfig --od-gettemperature. This will list all available ATI adapters and their temperature(s) in Celsius.
To view the current frequencies for the graphics card(s) as well as the peak, configurable range, and GPU load, run aticonfig --od-getclocks. The OverDrive support does extend to cover multiple ATI graphics cards, including those bridged together using CrossFire. If dealing with multiple GPUs, add the --adapter= argument with the adapter number, which is available when running aticonfig --list-adapters. When running in CrossFire though we have experienced some problems with the GPU load not being properly reported and it staying at zero percent usage.
Prior to setting any new clock frequencies, ATI OverDrive must first be enabled. This requires running aticonfig --od-enable to confirm you understand the risk of overclocking and that it may result in dangers or stability problems.