Can you Overclock 2 video cards in SLI at the same time?

[MrToilet]

Question in title- is there a program that allows you to overclock both video cards at the same time? I voltmodded the GPU's on both of my 7900 GT KO's, and would like to OC both at the same time.

Stock speeds are 500/1500, and ATI Tool says the GPU/Memory is artifact free until 650 on the GPU and 800 on the memory. I set the sliders, using Rivatuner, ATITools to 630 and 780, just to see if it will work, but when I try to run 3DMark 03 or 3DMark 05, I get weird memory artifacts. I'm guessing that only the primary card is being overclocked, and the computer can't handle that?

Thanks for any help.

 

[Matt2]

Both cards should overclock together. At least that's how it worked with my 7800GTs. I used Coolbits.

 

[MrToilet]

I got Coolbits to 640 on the GPU, and 3DMark 05 now runs- but 3DMark 03 gets stuck between game benchmarks. Not really sure what that's all about, since my system is stable in everything else, and temps are good (GPU 1=42C Idle, GPU 2=38C idle, CPU = 39C idle)...

 

[lopri]

The 'master' card has the say when it comes to OC'ing in SLI. If your master card is capable of a certain frequency and the slave card isn't, Coolbits will still approve the master card's clock but you might experience artifacts or instability in 3D, due to the slave card not being able to keep up.

 

[40sTheme]

There is no master-slave in SLi, is there? I thought that was only the original Crossfire...