yeah I'm with @rrusciguy (he gets me)... 25% isn't only TPT usage (and 25% does NOT mean 1 core usage)... it's also windows services, anti-virus, anti-spyware...
when im trying access to pentagon.gov it shows blank screen before saying "404, not found"(Oh! now it redirects to defence.gov), this means that there is ASP or smth like this on this page!!! The are trying to hide their page. I hope if i'll put smth in query string it will interact! (only last sentence can be interpret as joke...)
@rirozizo Most system programs will switch to a different core when the one the program is using starts to get full. I usually clock in around 32% when in a laggy sim. (25% for PT, 12% for background applications).