I have a Sapphire Vapor-X Radeon HD7950 OC edition graphics card. It runs at 850 MHz using the regular BIOS and at 950 MHz using the Boost BIOS.
I'm using the Boost BIOS. When computer boots, the card runs at 950 MHz when under load, as expected. I then use Trixx to overclock GPU from 950 to 1150 and memory from 1250 to 1400, using a +20 power setting to make it stable. It runs well, can run tests and games for hours, doesn't overheat, has no artifacts.
However, when I launch any GPU-accelerated video player, such as VLC or SMPlayer, frequency immediately drops to 850 (not 950!) and memory drops back to 1250. It stays there as long as the video player is opened, even if it paused. When I close it, I have to reset the overclock in Trixx and do it again to get back to 1150/1400.
Disabling 3D acceleration in the video player makes the problem go away but then the player is obviously a lot less usable. I need the overclock to run modern games, the difference is crucial for achieving good FPS in current games.
What is the reason for this behaviour? Can it be altered so that my video players would be properly accelerated and would not affect my overclock?