with Yosemite 10.10.3 and Intel graphics no problems found yet. Was running one evening without crash.I've not tested USB yet, in the past (with F5) there were freezes if i used USB2.0 and USB3.0 devices at the same time both on USB3.0 Interfaces.Processor: i7-4790KEdit:2'nd evening without freeze despite heavy USB usage (HD clone to external USB drive). This looks promissing...2_nd edit:After three days without freezes, they are back. Without any change on OS or BIOS. So no improvement from BIOS update with respect to random freeze....