Whenever a CUDA or OpenCL is started, the graphics card is limited to a lower power state called P2. This power state limits memory speeds to 6000Mhz on 900 series cards.The use of programs such as PrecsionX and Afterburner only affect memory speed in the P0 state, which is used for most other 3D loads. GPU speeds are not affected in P2, and may be increased normally.