New GPU shows its name/details but won't get to BIOS

[ZeroCookie]

I've been searching for a solution to this problem, but I haven't seen anyone with quite this problem.

I upgraded from a GeForce GTX 560 to a (used) GTX 780 Ti and I can't get it to start up. I don't know if it's broken and maybe I should just RMA it, but I'd like to get it working if possible.

System Info:
Intel Core i7-3930K CPU
Gigabyte GA-X79-UD3 Motherboard
Corsair 850W 80+ Platinum PSU (I thought the PSU was the problem so I upgraded my 700w 80+ Bronze Cooler Master model to this one as of today)

-With the old card, everything is working and runs fine.

-When booting up with the new 780 Ti, the card powers on, lights up, and fans spin.
-Then one monitor shows the Gigabyte BIOS splash - but the splash is the wrong size (small on the screen with black around it) and the buttons do nothing.
-Eventually after a few minutes the other monitor (the one I usually boot from) shows the text indicating the graphics card model and firmware, with a blinking underscore cursor underneath.

That's it. It doesn't go farther than that, and I can't get into the BIOS at any point either.

Any useful suggestions (including give up and RMA the thing) would be greatly appreciated! I've been pulling my hair out for days over this thing.

 

[ZeroCookie]

With some more looking around I found that some people were having GPU trouble with my type of motherboard, so I updated the BIOS to the latest version and the new card works.

I guess the lesson is (for posterity): newer GPU with an older Gigabyte mobo requires a BIOS update.