I have just set up the Intel 865 w/800Mhz bus speed, hyper threading & 2 channel mem using(1)gig 333Mhz DDR ram on 2 channels + 2.8 GHz P4/c <-(c) is w/hyper threading, and 800 Mhz bus speed. Incredibly fast................ but does not like PT-le in the least bit. I was able to work around the issues with PT-tech support. 1. Disabled smart power management completely. (I have to manually turn off system like win95 was (it is safe to turn off your computer - then just push the off button manually) 2. Disabled hyperthreading completly. PT will not work with it (maybe 6.1 will???) 3. modified swap file (maybe related to the high mem, or the two channel aspect??? I look at it like this. I have the 865 with some features temporarily turned off. I basically downgraded this set up. When PT can utilize the hyperthreading, I can turn these features on without a future upgrade. Finally I am ahead of software technology and am upgrade safe for a few months. It was frustrating though to have PT's install fully fail repeatly until these bugs were worked around. Perhaps, if you want a clean setup, stick with 845 unless you are prepared for some workarounds. I'm not sure if 875 is sim to 865 in these respects, but if it is you will have some discovory issues at installation.