Hi Tech Legion posted a review on the Thermaltake ISGC-400 CPU Cooler

Recently I built a decent AMD/ATI based system for gaming that was built in the NZXT Guardian 921 case, which is a normal size mid tower gaming case. This case, though roomy enough to accommodate a 4870 X2 graphics card, was unable to house a tall heatsink, such as the Titan Fenrir or Thermaltake ISGC 300, comfortably without removing the case's side fan and having the heatsink touching the side panel acrylic window. Now this left me considering taking the system back out and using a different case, but then I realized that I had received a new heatsink that might just fit and provide the performance I would need, and it was even a part of the silent gaming series from Thermaltake.

Thermaltake ISGC-400 CPU Cooler Review