I had a perplexing problem in my AMD HD 7850 2GB/AMD FX-6300 desktop running the Win10 TPx64. After each boot or log-on, the CPU & GPU would run as they normally ran under Win8.1x64, the cpu under Cool'nQuiet & the GPU under AMD's Ultra Low Power setting. Under 8.1 the GPU would run at 300MHz core/150MHz ram while web-browsing and otherwise not running games or other software that demands full power ; my CPU is set in Windows Power Options to run @1400MHz until full power is needed. Full power for the GPU is 1GHz core/1200MHz ram, and for the cpu full power is ~4.5GHz.
The problem I had was that after some twenty minutes or so had lapsed under Win10TP, after either a boot or a log-on, both my GPU and CPU would mysteriously ramp up to full power, even when doing nothing more stressful than web browsing--or even doing *nothing* except booting up and running the desktop. The only way to reset the proper low-power-profile for my cpu & gpu was to reboot or log-off and then back on--and then 20 minutes later everything would ramp to full power again. Like clockwork.
I tried a great many things and consumed a few hours of web-searching and experimenting (including uninstalling all of the Win10TP preview updates) before finally nailing down the culprit: the AMD FUEL Service in the 14.7RC3, 14.9WHQL, and the 14.9.1beta drivers (the only AMD Catalyst versions I tried under Win10TP) should be disabled under the Win10TP in any system running both an AMD GPU & CPU. (I reinstalled the Win10TP updates after seeing they were not the cause of the problem.)
Disabling that service stops the problem completely, and does not limit the Catalyst CC in any way as far as controlling the gpu is concerned. The only "feature" removed from the Catalysts by disabling the AMD Fuel Service are the CPU controls for CPU overclocking and managing the power profile of the CPU (these features only appear in the Catalysts if you are also running an AMD cpu.) They are completely redundant to the Windows' Power Option controls and of course the cpu clocking options I control through my UEFI.
Apparently, Win10TP currently does not play well with the AMD Fuel Service if you have both an AMD GPU & CPU and you are running any of the latest three Catalyst driver releases from AMD. Under 8.1 I had no such problems, so I suspect that this won't be completely fixed until AMD releases a Win10TP-compliant GPU driver.
Oh, man, was I ever tricked...! The AMD Fuel Service had nothing to do with it. Instead I had been hit by a nasty little piece of malware disguising itself as "steam.exe" but designed to turn my box into a BitCoin Miner...! Naturally, when the software activated my GPU and cpu ramped up to full power...!
Read all about it here:
The new "\AppData\Roaming\Steam\Reversed\steam.exe" BitCoin malware: How to detect and remove it :: Help and Tips