Multiple GPU Mining Issues

[dalexc]

Hi everyone.

I've been having this issue for not days, but months. I've tried every solution under the sun and I still cannot figure out how to get my multi gpu setup working properly. At this moment, there is only one currently working. The second one was just fine last night, but I woke up to that having issues. What bothers me is that they all work - individually. Simultaneously, there's always an issue. So I know the gpus not broken. They spin when I plug them into the motherboard. That's it. Windows does not recognize them.

First the specs:

Motherboard: MSI z77A-GD65
GPU: XFX R7950 (trying to get 3 working on same motherboard)
Ram: 8GB Ram
HDD: 120 SSD
PSU: LEPA G 1600W Gold Rated P
Windows 7 Home Premium

Things I've tried:

RMA both motherboard and psu. Nothing
Reinstalled Windows - yes I've wiped it out entirely. Nada
Reinstalled GPU drivers from scratch - again nothing.
Unplugged and plugged in GPU just for the heck of it - Nothing.

If there's anything here that I am missing, please do let me know, this mining stuff while I do enjoy is driving me insane.

[crazy987]

Can you try putting them in diffrent slots?
Also, do 2 cards work?
Try a diffrent type of motherboard?

[dalexc]

I tried different slots and yes they do work. 2 cards were working as of last night.

This is the 3rd motherboard I am trying.

[crazy987]

I tried different slots and yes they do work. 2 cards were working as of last night.

This is the 3rd motherboard I am trying.

Ok, but the 3rd same type? (z77A-GD65)
I'd suggest trying a diffrent type of motherboard.

[dalexc]

I tired different motherboards as well.

Also tried an AsRock Extreme. Still nothing.

[crazy987]

I tired different motherboards as well.

Also tried an AsRock Extreme. Still nothing.

Whats your cgminer start line?

[momchilandonov]

What exactly happens. Windows doesn't find the third card? What is device manager showing? Are you using PCI-E 1 to 16 extension? Is it possible that some of the 6-8 pin power connectors for the VGA's are not exactly the same? Like some taking power from a Molex and not straight from the PSU or 2 pins sharing one cable which is splitted into two? I've had an R9 290 not working with 350W PSU Fortron because it simply didn't liked the 6 pins for VGA or wanted specifically 8 pin and not 6 pin VGA power connector in the 8 pin slot.

[dalexc]

What exactly happens. Windows doesn't find the third card? What is device manager showing? Are you using PCI-E 1 to 16 extension? Is it possible that some of the 6-8 pin power connectors for the VGA's are not exactly the same? Like some taking power from a Molex and not straight from the PSU or 2 pins sharing one cable which is splitted into two? I've had an R9 290 not working with 350W PSU Fortron because it simply didn't liked the 6 pins for VGA or wanted specifically 8 pin and not 6 pin VGA power connector in the 8 pin slot.

Nothing happens. That's the issue. It's not in device manager. It's as if the card does not exist. The only existence that it shows is the spinning of the fan itself. That's it.

I'm not sure what kind of extensions I was using before. I don't think it's the 16 extension as the end that I am plugging into the computer is rather short. At the moment, I plugged the other two directly into the computer and still nothing is happening. I downloaded Ubuntu thinking it was an Windows issues and getting the same result. What the heck is going on.

[momchilandonov]

What exactly happens. Windows doesn't find the third card? What is device manager showing? Are you using PCI-E 1 to 16 extension? Is it possible that some of the 6-8 pin power connectors for the VGA's are not exactly the same? Like some taking power from a Molex and not straight from the PSU or 2 pins sharing one cable which is splitted into two? I've had an R9 290 not working with 350W PSU Fortron because it simply didn't liked the 6 pins for VGA or wanted specifically 8 pin and not 6 pin VGA power connector in the 8 pin slot.

Nothing happens. That's the issue. It's not in device manager. It's as if the card does not exist. The only existence that it shows is the spinning of the fan itself. That's it.

I'm not sure what kind of extensions I was using before. I don't think it's the 16 extension as the end that I am plugging into the computer is rather short. At the moment, I plugged the other two directly into the computer and still nothing is happening. I downloaded Ubuntu thinking it was an Windows issues and getting the same result. What the heck is going on.

The cards could need an attached monitor for their cores to start up which would be VERY DUMB for modern and expensive cards. I mean why would you but a 500+ $ video card? So it doesn't work? This is the only logical explanation to your problem. Try attaching at least one monitor in the slot of each card before starting the computer.