Vmod 3850 through BIOS apparently IS possible....

[Bo_Fox]

Hey guys, I have an HIS 3870 Iceq3 turboX 512mb version that clocks at 735/980 default. It's a beautiful blue card that matches my UV purple computer.. hated that red ATi color since it was the only thing that didnt go with it.

Sometimes it locks up with a white screen in 2-D mode, so I have to keep it overclocked in 3-D mode all the time via Rivatuner to prevent switching between 2-D and 3-D low performance. Even when overclocking is disabled, it still crashes once a day when doing intensive 2-D tasks like scrolling down this page or moving a window around. When I do that, it actually uses up to 50% of the GPU as shown in CCC and Rivatuner, and the card instantly clocks up to 3D low perf. mode for a second or two and then switches back to 300MHz idle mode. The switching could happen quite frequently back and forth.. that never happened with my X1900XTX (it would stay in 2D mode unless I fired up a 3-D application). I guess ATI is trying harder to push low-power consumption in 2-D... Perhaps the 2-D voltage is too low or the voltage ripple changes from frequent switching goes too high or too low?

Anyway, I can overclock it to 755 core/ 1040 memory while it's absolutely stable in all 3-D applications. There aren't any ATItool artifacts until I go up to 800/1050 but it crashes in games like Quake3 with Vsync disabled and bringing down the console command (by pressing ~). I think that this method (Q3A console) is the quickest way to test your GPU stability since it was best at finding GPU errors on all of my previous video cards (6800Ultra, X800XT, etc..). Strangely, ATI's own CCC overdrive auto o/c tool pushes my card all the way to 860 Mhz before it artifacts all over the screen... USELESS!!!

If you guys want my TurboX 735/980 Bios, I'd be happy to upload it here. I'll do that anyway because I do not know how to edit the BIOS voltage and would love to be able to overclock it higher than 750 core.