I want to downclock my Ati Radeon HD5870's memory to 300Mhz and overclock it's core frequency to 930Mhz. I can do this on windows using Ati Tray Tools.
On linux, the only way to do this so far has been to use Ati Overdrive:
$ aticonfig --odgc Default Adapter - ATI Radeon HD 5800 Series Core (MHz) Memory (MHz) Current Clocks : 850 1200 Current Peak : 850 1200 Configurable Peak Range : [600-900] [900-1300] GPU load : 97%
As you can see, the problem here is that it won't let you select anything that isn't in the "Configurable Peak Range", when it is entirely possible on Windows and perfectly safe to do so (within reason).
Do you know any way to set the required frequencies on Ubuntu linux?