I'm having some problems running Mavericks and Yosemite on my Mac Pro 1,1. With the evga 650 I won't always see the login screen. This happens about 75% of the time for both Mavericks and Yosemiti. I expect to not see the boot screen, however not seeing a login screen pretty much makes the computer unusable. For Yosemite, I used SFOTT (http://oemden.com/?page_id=531) to get it installed. I would like to upgrade to the mac edition gtx 680 (http://www.amazon.com/EVGA-GeForce-DisplayPort-Graphics-02G-P4-3682-KR/dp/B00C88RHUS), just because having a boot screen would be nice and the used price on eBay is within my reach. I'm also sick of having to reboot the machine constantly. I'm wondering if this card would work with my aging Mac Pro. Any help is appreciated keeping this ancient machine running. Thank you!