AMD issues statement on R9 290X speed variability, press samples
Based on feedback from the enthusiast community, we’ve implemented an all new PowerTune mechanism in the AMD Radeon R9 290 series that exploits the full capability of the individual GPUs rather than clamping performance to a least-common-denominator type of capability level. This has the advantage of improving overall performance but does result in some degree of performance variability. These changes will also result in some degree of run-to-run test variability based on environmental and operational conditions in un-controlled test environments.