OCC has published a new review of the XFX 9600 GT 512MB

To overclock the XFX 9600GT I used Nvidia's Ntune software. I started at the default clock speeds of 650 on the core and 900 on the memory. From there I worked the core and memory clocks up until I found a good balance of clock and memory speed. The final speeds were 727 on the core and 1033 on the memory. To run these speeds I set the fan control manually to 100% to maximize the cooling capacity of the single slot cooling solution. For a $180 dollar card, a core speed increase of 77MHz and a memory speed increase of 133 MHz are not to shabby if you ask me. At no point did the temperatures get out of hand, which is surpriseing considering the size of the heatsink.

XFX 9600 GT 512MB Review