What actually causes a computer/program to run slowly?
noodle: typically, i/o operations, which can be caused by numerous things.  or, if you're just crunching some serious numbers.if your "computer is running slow"(tm), its probably from paging/thrashing due to not having enough ram or having too many things open.  i've fixed too many "my computer is running slow" problems that ended up being someone having 100 IE windows open at once.