Ever since I've installed my Alpenfoehn "Brocken" heatsink, which, like most coolers, happens to blow upwards instead of backwards on a AM3 board, I've noticed that sometimes the CPU throttles to 7.5x multiplier. At first I was puzzled, but upon touching the chokes with my finger, I quickly ascertained the problem - with AMD's stock cooler, the fan blew down on the motherboard, and the air was directed sideways by the heatsink fans, flowing over the VRMs to the left of the socket. There was a fancy looking heatsink from Asus, but the chokes weren't covered. With this aftermarket cooler that blows upwards, the chokes got no airflow at all. Actually, I don't know the maximum temperature for chokes, maybe the MOSFETs under the heatsink were the ones overheating, the whole area to the left of the socket isn't getting airflow I think.
Have you guys run into this problem before? What have you done to fix it? Personally it's fast enough for me at 2GHz as well - but that does defeat the purpose of me overclocking it if it throttles itself every now and then.
I could reverse the 140mm fan on the top of the case so that it blows air back into the case instead of out of it, but then the CPU fan are blowing in the opposite direction.
Mothership: Thuban 1055T@3.7GHz, 12GB DDR3, M5A99X EVO, GTX470+Icy Vision Rev.2@840/3800, Vertex 2E 60GB
Supply ship: Sargas@2.8GHz, 12GB DDR3, M4A88TD-V EVO/USB3
Corsair: Macbook Air Ivy Bridge