So i previously had a XFX 7950 that throttled identically to this Powercolor 270 clocks down and up rapidly and usage fluctuates back and forth from 64% to 100%. the 7950 throttled like this even before i put a water block on it, i've only every used a water block on the 270. all temps are good What the hell is going on?
Edit: just tried uninstalling afterburner and am using sapphire trixx same issue.
Is this happening under load (benchmarking etc)? At idle? Gaming?
It will throttle depending on the workload.
If @ idle you may have some background malware-miner working away. Not good...
Run say Furmark and if you still see the throttle spikes during stress testing and temps are good. Then look to the drivers.
Uninstalled, cleaned (guru3d DDU), re-installed drivers?
Tested cards in other machines
Tested in a linux environment? - there is a linux version of the Heaven benchmark available