Overclocking question

I unlocked my radeon 6950 2gb to 6970, got 1536 shaders counts. I use MSI afterburner to OC the clock and memory. But why its only limited OC to 840mhz and memroy to 1325mhz in afterburner? Can't go any higher. I want to run the card at 880mhz and 1375mhz.

I tried to use trixx but my screen keep getting flickering. Any help, tips on how to fix this is much appreciated.

I think MSI can't go higher than what CCC would allow you. Give this a try:

http://www.techimo.com/forum/graphi...9-enable-higher-overclocks-ccc-reg-entry.html