Using Riva Tuner as the overclocking utility I was only able to get the core 100% stable at 320MHz. It would overclock to 325MHz just fine, however, it would lock up in 3DMark2001SE and Code Creatures. Every other benchmark would run fine at 325MHz though. But because I needed a 100% stable overclock to test in all benchmarks I had to keep it at 320MHz which is just an average overclock for the Ti 4600 GPU. This goes to show that the cooling is not the only factor in overclocking the GPU. Chip yield can also determine how high you can overclock the core; some are just able to clock higher than others. I was able to overclock the memory all the way up to 370MHz (740MHz DDR)! This is with the stock cooling right out of the box.