Task Manager never shows more than 12.5% CPU usage whether I'm running old apps or new ones that have check boxes for "use multiple cores," such as encoding programs. Even WinRAR never uses 2 or more cores, and we all know how slow IT is. I know all the cores work because I can run "Folding@Home" cores on each one. Even 8 all at once, but no other single program uses more than one. Do I have something not set right, or is this the norm? Programs I've noticed not using muliple cores despite their supposed capability: Xilisoft Video Converter Ultimate v5.1.37.0226; WinRAR 3.90; ConvertXtoDVD 4.0; TMPGEnc 4.0.7.32 System specs: Core i7-920 (watercooled); Asus Rampage 2 Extreme mobo; EVGA 9800GX2; 6GB OCZ Platinum DDR3; 300GB WD Velociraptor; Windows XP Pro SP3 (x86) (build 2600) DirectX 9.0c 1 person needs an answerI do too

If the program isn't written to split the processor-intensive workloads up into multiple threads, then the program likely will not be able to take advantage of the cores in the system. (Other processes' threads will run on other cores, of course.) That you seem to be able to create a "100 % CPU usage" scenario with F@H suggests there is nothing "wrong" with the configuration. You might check the specific program settings to see if there is some performance tuning option that can affect how it uses the CPU (adjusting for system responsiveness vs. speed, for example).

If the program isn't written to split the processor-intensive workloads up into multiple threads, then the program likely will not be able to take advantage of the cores in the system. (Other processes' threads will run on other cores, of course.) That you seem to be able to create a "100 % CPU usage" scenario with F@H suggests there is nothing "wrong" with the configuration. You might check the specific program settings to see if there is some performance tuning option that can affect how it uses the CPU (adjusting for system responsiveness vs. speed, for example). All the programs I mentioned DO list multi-thread as optional and I did/do select that option. F@H isn't a good example because it does NOT use multiple threads. It is able to run 8 instances of itself at once, each instance set with affinity to one specific core. I only mentioned F@H to prove that all 4 cores and hyperthread cores work.

There is an SMP - symmetrical multi processing, what having multiple cores means - client for Folding@Home. Have you tried that and does it behave as expected? Otherwise, my guess is that for most of your programs they are being limited by disk speed (even with a top-end drive) or perhaps memory. Not too many things are CPU intensive. Folding@Home is one. XaoS, a fractal explorer program, is another - it's single core mind.