orthos find hardware failure when prime95 dont

hi,

i just ran dual prime95 for 2 hours with no error, at 400 * 7 on c2d 6600 at 1.3500vcore and memory at 2.1v 4 4 4 12..curious about orthos cause pple seem to be agree that it stress more the cpu than does prime95 i ran dual orthos, and after only 2 min into the test one of the orthos stopped and i got a beep...looks like prime95 is not the most very stressfull software to test our o/c maybe ? also what does this beep ? is it a beep from the software or a beep coming from my motherboard ? cause it scared me

im always checking them and they are under 55

please help,

i dont know how to launch 2 dual orthos, i start 2 instance i choose then blend stress cpu and ram for both but when i click on start just one orthos seems to work...i can run dual prime95 for hours but i dont think i have configured orthos correctly. do i need to put something in the shortcut command like for prime ?