Yea, that's a revision 2 GT. I really dont know why overdrive isnt enabled for it, but even if it was, I would recommend ATi Tray Tools(<--click) to overclock with. I dont use Overdrive although it is enabled with my GT.
Thanks for the tip.
I just have 1 more question how can i find out the temp of the gpu?
The program I linked you to has all that. It can give you a temp guage down in you disk tray by your clock.