Just put in Radeon 5870 on a early 2009 Mac Pro running the latest every thing with a Mac screen. It starts up well and then graphic lines all over the place and bits of the screen missing. Is it the card, the Mac or could it be me.
Is the display cable connected properly or is it damaged?
I had something similar happen when my 8800 GT died.
The original card still works? Try it.
You do have both 6-pin auxiliary power cables connected to the card, right?
My 5870 is working fine in my 2009 Mac Pro....
Yes I have it back in. Have a man called "The Digital Plumber" calling in next week. I will update later. Thanks for all your help.
You did try re-seating the card in the MacPro or trying an alternative PCI-e 16x slot ?
If it wasn't properly installed even by the tiniest millimeter it could have created this issue, though like others I suspect it was probably a lemon.