Hi Stanw. That drive will work on your 1.1 Mac Pro. Though try to get a HD with a bigger storage capacity like 1TB or more as it's better optimized. Hitachi HD and WD are among the durable brands. According to this article, Hitachi HDs has the lowest failure rate, http://arstechnica.com/information-technology/2014/01/putting-hard-drive-reliability-to-the-test-shows-not-all-disks-are-equal/Can a Maxtor SATA Ultra 16 300GB 7200RPM be used with a 1,1?