I paid $200 to have them flash my GTX 970 and i get it back in the mail, install drivers and everything and install video card and reboot and its black screen all the way to desktop. Any advice other than contacting macvidcards? Excerpt: http://www.macvidcards.com/what-are-the-benefits-of-buying-a-flashed-card.html What Are The Benefits of Buying a Flashed Card? A Mac BIOS enables you to see the gray boot screen at startup (where you see the Apple logo and hear the iconic boot chime). This is very helpful for users who regularly need to switch boot drives and operating systems.