hi there! I need buy tomorrow a mac pro 2.8, I read a lot about that are a so silence machine quiet, that sounds perfect, but I think, if add the 8800GT and more hard drive 500GB by example, the sound of the machine increse? that are not the same quiet sound? more work or fans or something... I think? PLAESE HELP ME SOME COMPARATION ABOUT THAT? I want more performance but same quiet machine thanks!!