700mhz wall on HD4850 is smashed.

[Factotum]

I tested overcloking 4850 in 3DMark06, voltmod, cooling with Accelero S1
625/2000 (default): 12 745
800/2200: 14 238
800/2400: 14 608
825/2400: 15 375
830/2400: 15 033
840/2450: 15 401
850/2000: 14 057
as seen after 825 MHz for GPU performance has ceased to grow, even more at 830 MHz on the core see failure. I repeated the tests with 825 MHz and 830 MHz - the differences were within the limits of errors
I think in DX10 frequency dependence productivity of GPU / GDDR will be similar