I have 2 Zotac GTX 570 AMP editions in SLI. I bought them at different times. They are the exact same model # but one has a newer BIOS version. Do you think I could be taking a performance hit of any kind because of this?
I'm sure there is a chance of bricking it. It's a chance I will take if it would be beneficial in anyway to getting them running the same BIOS. But if there is no benefit, then I won't bother.
By the way I have not increased the factory overclock (but may do so).
Having different bios in sli should not have any impact on performance.
Flashing the bios in a video card is pretty easy. I have used nbitor to flash a 470 bios onto a 465, I used to adjust the bios of all kinds of cards from 8800gt up to 470s. Never messed with anything newer than the 470 though.
Keep in mind you can never really brick a video card as long as you have another working card, you can always re-flash the bricked one. All you would need is a working bios and another card plugged into the monitor so you can see what your doing. Of course you could flash a crazy overclock and burn the thing out, but that different.
I keep an old, like 1995, pci video card around. If the flash goes wrong I just stick in the PCI card and boot with the screen plugged into that. Then just reflash.