MSI R7970 non Lightning OCing

Hello community. Just wanted to ask what people are OCing their 7970 non GHZ editions to? Mine came factory OCed to 1010 1375 memory clocks. Just installed an Arctic 7970 aftermarket cooler which lowered my temps immensely. Would like to find out what the potential of this card is. Had it OCed to the standard 1125 etc without voltage increases, would like to know what it can do with changing the voltages and what not.

Pretty hardware savvy, but havent delved into OCing too much. But since I have performance oriented hardware, would like to push it farther.

Another question I have, this BIOS switch on the top of the card, its set in position 2, what does setting it into position 1 do? Cant find too much info on their site and dont have the manual anymore. Something said that switching into position 1 would unlock the card for OCing it completely. Anyhow would appreciate some info on what people are running their cards at, what settings they are using etc. Thank you for reading my wall of text  

Tom