Well the Core 2 Duo doesn't produce that much heat to begin with, but for normal use the stock heatsink should fare well. If you want better cooling, buy a Zalman CNPS9500-Cu, ThermalTake Big Typhoon or ThermalRight SI-128. Those should cool the Core 2 very nicely, and it doesn't produce much heat. Maximum PC's X6800 only rose 3C in temperatures when they had their CNPS9500-Cu running passively with the fan unplugged. It ran stable for hours, and never crashed or got a single error.