I am using Ninja (Ver A) with 120mm Scythe on my quad Q6600 undervolted to 1.0Vc. With ambients around 27C, I am idling in mid 30s with nearly silent operation. Running 3.0ghz at 1.25Vc, I was in low 40s and mid 50s fully loaded, fans were audible but still pretty quiet. I like cool and quiet PC!