ADL (AMD Display Library)
This package wraps the AMD Display Library 3.0  using ctypes. You do not need to install the SDK to use this package, and no compilation is required.
Also included is a sample Python script using adl3 called _atitweak_. This script can list your adapters and optionally sets core and memory clock speed and voltage per performance level.
For example, to downlock your memory to 300MHz, you might use this command:
$ atitweak -m 300 Setting performance level 0 on adapter 0: memory clock 300MHz Setting performance level 1 on adapter 0: memory clock 300MHz Setting performance level 2 on adapter 0: memory clock 300MHz
WARNING! This software can damage or destroy your graphics card if used incorrectly.
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-  http://developer.amd.com/sdks/adlsdk/pages/default.aspx
- AMD Display Library 3.0