Anyone running 4 290x on the same motherboard? Please help.

[Barrotek]

Hi there, I was wondering if anyone has had success with 4 or more 290xs on the same motherboard?
I've tried two motherboards so far, an ASus A88X-Pro, and a GIGABYTE GA-990FXA-UD3.

My setup:

1 1000w PSU
1 800w PSU
Add2PSU
The 1000w powers 2 GPUs and the CPU, the 800w powers the other 2.
BAMT for the software.

For quick checking, at the moment I have all on powered 1x-16x risers, with power hooked to each, from the correct PSU.
I can bring up 3 cards in any configuration no problem.
No matter what configuration I try, any time I bring up that 4th card, BAMT will start to fire up, but then the screen will go blank and the cards go to that idle
speed they normally go to right before they normally ramp up(right before that white line shoots across the bottom of the screen) hard in a normal working configuration.
But it just hangs there indefinitely when 4 are plugged in.

I have verified that all risers and all cards are good when hooked up individually or in any combination of 3-at-once.

On the A88X+, a friend has the same board and he was able to get 4 280Xs running no problem on his machine.. But it doesn't seem to work with 290s..

Anyway, if anyone has any idea's I'd love to hear them.. I'm completely stumped as to where to go from here.

Thanks for reading.

[Trance]

You might have a power issue brother... you must understand how much power each GPU is sucking in considering its running at high hash rates! I ran into this problem when I did not do my research and purchased a Motherboard that did not have sufficient bus speed along with a power supply that was not enough, no such thing as too much power within a PSU, especially for what you are doing! Goodluck!

[pw4x3r]

Yeah that most definitely sounds like a power problem... R9's pull approx. 21 amps a piece. You need to make sure your amperage on your 12v rails can support that. Not common but sometimes things can get weird with two PSUs at max load also.

I run one Thermaltake Toughpower 1300W running 4x R9s on the motherboard with some low end Haswell, no risers. Board has additional PCI-e power input ;]  Just enough from that PSU to make it happen

[Barrotek]

Thanks for the comments, folks. My cards draw about 300w a piece running hard, but I'm not even getting to that point where they ramp up at all so I'd be surprised if they are even running 200/piece when they bomb..  I have a total of 1800w so I'm having a hard time with the power issue being my problem, but the responses here and from a couple chat rooms have all brought up the power issue.. My friend with the 280xs is coming by tomorrow with his rig and he has a 1050 so I can at least ramp my system up to 2000w+ to see if that does any good.. I'm going to drop my cgminer settings down to a minimum so everything is for the most part running idle and see how that works..


Thanks again for the responses and any other thoughts are welcome..

[Barrotek]

Just a little update.. ATIFlash shows all 4 290Xs but still can't get the 4th up in BAMT.
My buddy dropped by this morning with his 280x and popped it in.. It works fine.. 3 290Xs and 1 280x running no problem.. We're stumped.

I'm going to install windows on one of my rig's and see what that shows.. Maybe it's a BAMT+290x issue or something odd like that..

[PDcologne]

Hi, I'm using the gigabyte 990fx board - used 2 before I could get it to work using 4 asus 280x on risers...

Not sure if this is the same issue your having but I could never get the 4 cards to work via Ubuntu... I bottled up windows and no problems...

For info I'm using 2 rm750 psu so power should be no problem for you....