it used to keep my old thenom x3 below 40C under load, and it's performing very well keeping an overclocked A6-6400K really cool, i always have the fan on low too.
they're awesome, i have the older blue led one and i hope it never dies.
http://www.thermaltakeusa.com/products-model.aspx?id=C_00001242
consistently low temps, can't fault it.