I'm putting together a PC using a 3.2 ghz Northwood Pentium 4 and a Intel 865PERL motherboard with a Zalman 7000-A AlCu heatsink and Arctic Silver Ceramique. The CPU temps I'm getting are 43c from the BIOS screen. This is with the motherboard in the open air on a table, not installed in a case. When I install it in a case (Silverstone LC-10) even wit all the fans hooked up but no hsrd drives or expansion cards installed the temp rises to 50c. I've reinstlled the heatsink several times (after cleaning it and the CPU and reapplying the Arctic Silver) and the temps stay the same. I'm trying to figure out why my CPU temps are so high. Since this computer is to be used as a HTPC I dont want to load it up with more or higher powered fans. Am I using too much thermal compound or too little? Could anything else be the source of the problem? Thanks.