I know this is a late reply but its GFE/ShadowPlay that causes your GPU clock to max out and never down clock on the desktop. If you go to Windows task manager you and click "NVidia Streamer Service " or "NVidia Capture Server" and "End Process", you should see your GPU clock return to normal. Its a known issue that arises every so often.. I had to revert back to GFE 126.96.36.199 which allows my GPU to down clock with no problems. Its a weird bug or something because it will happen to others when I have no problem on the same GFE version.