I got my Vanilla EVGA GTX 580 yesterday it runs at a default voltage of 1.0125. I'm about to start the process of testing the overclocks, I would like to determine opinions based on tools used to test artifacts. I'm leaning towards using GPU-Tool however I noticed that it mixed up core and shader clock readings. How reliable is the auto "find max" function?

Based on the adjustments options available with the tools available to me it doesn't seem necessary to flash my BIOS. Is it absolutely necessary to flash my BIOS to attain higher OCs?