Just installed this on my HIS 4870x2 yesterday . Dropped my idle temps by a whopping 50c now idles at 33c and load down to 42c from 90c using Furmark. Instructions where easy to understand and it mounted properly with no mods. I am very happy that I purchased this gpu block , it really tamed the beast that is the 4870x2 :) It may not look as nice as some other brands but it works awesome. Higly recommend to anybody looking to wc their 4870x2.