Whats going on with my 6800 GT?

[stayfrosty]

If i overclock it to more than 420mhz on the core my 3dmark scores actually start to go down, I dont see artifacting or anything wrong with the picture It just gets lower frames, by alot. its watercooled and runs at 40C under load. Only thing i can think of is flashing it to an ultra to get the extra volts, please leave your expert opinions thanks.

[Rukee]

you have reached the limit of the GPU and it`s throttling. I see the same thing with my 6800 GT only at 440MHz. I tryed to freeze it with a Vapochiull at -35.0c and the clock speeds were exaclty the same, so I`m thinking it`s internal GPU limited somehow, not temp limited.

[stayfrosty]

so would flashing it to an ultra get me anything? or is this still unknown territory