Triple Asus 7970 DC2T stability issues

[r3zn0r]

when running 3 of these cards i get inconsistant results. if i get a crash during benchmarking windows will not load (hang on logo) untill drivers are removed (in safe mode) and the 3rd card is removed.

after i re-install the drivers i can add the 3rd card again but most times it crashes all games.

with the 3rd card removed everything works fine.

system specs

i7 3930k
asus rampage iv extreme
64 gigs gskill 1333 ram
3 x asus 7970 dc2t
1500w enermax power supply
vertex 3 240gb ssd

all 7970 drivers same results.

at one point yesterday everything was fine with 3 cards then i got a crash and it has not been stable since.

no extra overclocking at the time of the crash.

[HiVizMan]

What BIOS are you using and do you have the extra power connector installed?

[r3zn0r]

bios 1101 and the extra power is connected

[HiVizMan]

Please update your BIOS to the latest that Shamino provided.

And ensure you have enabled Gen3

If that fails to help try Gen2 setting.

Will check back later today

[r3zn0r]

Will try when I get home. What are the power requirements for these cards as 1 of the cards must share a 30a rail with other devices whereas the other 2 are on their own. Could this also b a problem? Is that 1103 BIOS or 1201 I should try or both?
Thanks

[HiVizMan]

Ooh I do not like multi rail PSU's for these cards, true they are not a power hungry as the 580GTX cards - I guess it should be fine as long as there are not to many other things on that rail.

[DougOtt]

Are you using three ASUS HD7970 DC2T 3-slot cards or the HD7970-3GD5 regular version?

[r3zn0r]

yeah 3 x 3 slot cards

im almost sure its the card as the bios made no difference and with that card in on its own the motherboard would get stuck on debug code 62, if it did get past it it would sometimes crash even just in windows and in eyefinity it would crash every game.

i tried it on the shared rail and on its own rail. same result.

ive got the other 2 cards back in and everything works fine. boots every time, eyefinity games run fine and no display corruption in windows. still im going to get a separate power supply and try that 3rd card powered by that and see what happens.

i havent tried Gen 2 yet with the other card as i forgot before i pulled it out.

[r3zn0r]

seems like these cards have a overheating VRM issue. with my fans up to almost full i can play skyrim without problems but if i have them on auto the game crashes randomly.

when will you be issueing a recall and replacement program with better designed cards?

[MarshallR@ASUS]

Dear R3ZN0R,

Where else have you read about 'an overheating issue' because this is the first we have heard of this. RD is now testing your situation to see if they can replicate the issue. The VRMs are overspeced with a design to run cooler than the stock card.

Are you sure the lowest card is getting enough air? What temperature does it run at versus the other cards in your case? Have you tried swapping around the cards to see if it's just an issue with that slot or that particular card?