New Power Mac G5 Uniprocessor firmware update posted (MacCentral) MacCentral - Apple has released Power Mac G5 Uniprocessor Firmware Update 5.1.5f2, a new release aimed at Power Mac G5s that have only a single processor. The update apparently corrects "unexpected issues" that have appeared on some Power Mac G5s after applying the first uniprocessor update, released earlier this month.