As long as the CPU temp stays below 71C, you should be fine. 60-65C is fine with Prime95 stress testing. My i7 920 stays just below 70C for the CPU and 75C for the 4 cores with HT/SMT on. According to this test, http://www.bit-tech.net/hardware/cooling/2008/07/06/gigabyte-g-power-2-pro-cooler-review/4
, the cooler actually does quite well on max fan speed. How high do you have the fan turned up? It doesn't do the best with the fan on 5V, so check the speed.