I recently got a mac pro 5,1 2010 with dual 2.4ghz processors. I originally installed a asus gtx 750ti with nvidia web drivers and cuda drivers. I had problems getting anything to display (besides screen share) so I switched back to the original 5770. I also installed a kingston predator hyperx pci ssd into port 4. I did a clean install, set the drive to boot disk and erased the original. I left the drive unencrypted to make logins easier. The computer works great except I have to do a nvram reset everytime I turn it on. If not it boots up like normal then goes to a screen with a circle with a line through it. I uninstalled the nvidia drivers, mainually removed the cuda drivers and did a clean os x reinstall. I still get a funky looking login window. I cant figure out how to boot the computer without doing a nvram reset. anyone have any ideas? Tomorrow I will be installing two x5975s (with lids), 16gb of 1333mhz ecc ram from owc and a flashed 7970 from ebay. The video card comes from a seller with 99% positive feedback, so I have my fingers crossed. I also installed a couple sata 2 velociraptors.