May 17, 2014
It’s known for a while that GCN radeons are low performers on 2008 MacPro using OSX 10.9
And the reason for this is…..
Apple fucked up some CPU power management resulting in videocard not running properly. plz fix.
Just remove AppleIntelCPUPowerManagement.kext and AppleIntelCPUPowerManagementClient.kext if you like to workaround it, speedstepping still works, cpu isn’t hot/cosuming a lot, still drops the clocks.