None, yet, my "certified" former employer knew less than i did, and he has been in the business of computers for thirteen years.. Tis a sad world we live in.. My former boss even was stupid enough to believe that using a stock intel fan and heatsink would be adequate for a pentium four 3.4ghz prescott with NO CASE FANS. of course, they got well over 70c, i told him and told him that was not good, that they should not idle above about 45 - 50c or you risk burnout, he didnt listen.. 'Till one blew its guts out from overheating while installing XP pro.. Scared the crap out of him, he was sitting there waiting for it to finish configuring, then, the CPU fried. However, i have failed to convince him that the ATI HyperMemory video cards are anything more than junk. I eventually quit the job for several reasons, the first reason was his incompetence, and utter stupidity, the second was when the craptastic offbrand PSU's that came with the cases blew out he blamed me, and the third, was that he wanted me to sign off on a computer that i did not assemble, which, he had repeatedly told me NOT to do. If he cant follow his own stupid guidelines, i dont see him as a competent employer, or person for that matter.