Mac Pro 2006 GTX 650 / GTX 680

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!

I posted this question in the Yosemite thread because it seemed like a better place. Sorry for the extra post.

I've actually logged in using screen sharing from a different computer, and the screen still remains blank after logging in. I did a bunch of searching today to try and solve the problem, but haven't come up with anything yet.

MacVidCards said:

If you can't memorize the log in procedure then get a flashed 7950/70 as the have boot screens.

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It's weird because when using screen sharing, I can see that the graphics card is properly recognized

So far that seems to be the trick, which is embarrassing Thanks! I didn't think that the Yosemite drivers were out yet.

MacVidCards said:

From the screenshot it looks like you don't have the Web Drivers installed

Try those

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