I have an X2 4400 in a sonata, 1 silent rear case fan and the PS fan, at idle the case is 30 C, cpu 35 c, and hard drives are 30 c, under Prime95 on each core the temps peak at 45 c and all others mid 30's except drives which are low 30's. This is overclocked to 2432 MHz. At stock 2200 speed temps are a couple degrees lower, and I have 2 raptors, 2 300gb drives, 2 dvd burners, 4x512 memory, stock HS and fan, and a Pabst PS(460w) with a 7800 GT in an MSI K8N Neo4 Platinum SLI board. Needless to say I am very pleased, our apt temp is usually 64-70 F. I was running a 2nd 120mm fan behind the drive cage but case temps were running 10 degrees hotter, just an fyi