Z77X-UD5H will not post with ATI 6950HD

[moneymark]

Bit puzzled on this one. I installed my new UD5H last night along with my crossfired dual 6950s. When I attempted to fire up the machine I got 1 long beep followed by 2 short beeps.  Looked up the code and it stated there was an issue with the graphics cards. So I pulled them both and plugged into the motherboard's dvi-d. The bios then came up this time. I upgraded the bios to F7 and booted into windows just fine. I then shutdown, put in the 6950s and restarted. Again I was unable to get the bios to come up.

I'm using a PC Power and Cooling 910w Silencer, i5 3570k, Gigabyte Z77x-UD5h, 2x4GB G.Skill Sniper DDR3 2133 in slots 1 and 3. Any ideas are much appreciated!

[moneymark]

Just replying in case anyone else runs into the same issue. I remembered that I had flashed my 6950s to 6970s, so I switched over to the backup bios and the system booted instantly. Odd that this never caused any issues before but it would seem that these new boards don't play nice doing that.

[Dark Mantis]

Hi and thanks for posting your results. I really can't think of any reason why they should do that as basically the upgrade just turns on the shaders that were turned off. It should be exactly the same as a standard 6970. Computers, huh! 

[hazlad24]

Hi

I also have same problem, and so does another on a forum im on.

Works fine in 6950 bios but wont display anything on 6970 bios, it also boots up but no display.

[Anogianos]

same here i have z77x d3h and a flashed 6950 HIS and it wont boot with the 6970 bios!!!, only with the 6950 bios... 

[Anogianos]

update, i flashed the board (z77) with the beta f11a bios but still no play, my graphics card 6950 wont start with the modded 6970 bios 

[Anogianos]

Z77 Sabertooth bios for unlocked 6950

    It has been confirmed that an unlocked 6950 will not work with the Z77 mobos.

    Need to know when new bios will be available.

also other manufactures have the same problem but i think they made a bios that addresses the issue...

[Anogianos]

i found a workaround for this bug, 
http://www.tomshardware.co.uk/forum/352078-15-trouble-unlocked-6950