bit-tech.net is looking at a 6600GT with a difference. This card from
Galaxy implements a dual BIOS and a buzzer alert to aid overclocking.

The Smart Flash feature works using jumpers that are located on the PCB. It's designed so that you can have two sets of BIOS information on the card and switch between the two at will, like with some of Gigabyte's motherboards. Unfortunately, the included documentation says very little about how the concept works. In fact, the best information that we found was on Galaxy's homepage, and that wasn't exactly clear - it briefly explains how the concept works, but doesn't give the user any all-important instructions on how to use it.

6600GT with Dual-BIOS from Galaxy