just built a economy system for my daughter, she had my old socket 7 750T-bird, new case, old Antec 300w, A-Open socket A AK77-600via, Sempron 2400+, 2x256 PC2700. Seagate 20gig, Liteon combo, 1.44 fdd, cost me all of $250. The wierd part was that the stock hsf is just a solid aluminum, no copper, i'm thinking cheap piece of junk, well guess what the cpu temp at idle is no more than 35deg C, my sons same cpu, different hsf, 45deg C, what the heck, both are using AS5 compound. My sons hs is stock aluminum with a copper plate 1"x1" screwed to the bottom, i applied as5 between the cpu/copperplate/alum finned part where my daughters is just between the cpu and alum hs only. now i dont know what is causing the huge difference in idle temps, maybe you can just get two cpus that have that much difference, but i'm definately going to look for a better hsf for my sons pc, for one thing he is a heavy pc gamer and beats that cpu like a near-sighted step child, hours of constant play, so hes the one that needs the good cooling.