ASRock 970 Extreme3 Rev2 - Not detecting more than 2 GPUs ???

[DoctorEvil]

As per the subject really.

I have read in a few threads on this forum that users are recommending / using this motherboard for 4x GPU rigs, but nobody mentions doing anything special to get the GPUS detected.  I have tried the usual tricks of putting all 4 cards on powered risers and shorting the presence pins on the 16x slots and just about every combination of all this.

I have put together two small LTC mining rigs using identical parts and they both behave differently in terms of GPU detection, which is both very odd.

Both of the small rigs are:
ASRock 970 Extreme3 Rev2 -- 2x PCIE x16 Slots,  2x PCIE x1 Slots
Sempron 145 CPU --Yes I know this is crap and was a mistake :-)
4GB DDR3 1333mhz   cl9
1000W Fractal Tessla PSU

GPUs are Gigabyte R9 280x's

On rig#1 I can get a max of 3 GPUs working by plugging GPUs in to both x16 slots and the 3rd GPU into the 1x slot in between the two 16x slots using a powered riser.  A 4th GPU will not be detected if put into the remaining 1x slot on a powered riser.  I have tried all combinations and this is the max I can get detected on this one

On rig#2  I can only get a maximum of two GPUs detected!  Again I have tried all combinations of GPUs in slots / risers, presence pin shorts, etc and whats really odd is that if I put a GPU in each of the two 16x slots it only sees 1 GPU.  With GPUs in both the first x16 slot and the middle x1 slot I can get the two working and that's it :-(

Does anyone have any similar experience with these ASRock motherboards and ideally any tips or what do you all think I should do?  RMA them, get them swapped if possible maybe.  This motherboard is supposed to support both dual and quad crossfire.

A huge THANKS in advance for any direction on this one as I am really baffled by it and its really driving me nuts!  My gut is telling me that I should have just stuck with Intel when it comes to Mobos and CPUs, but I thought I would give this combo a bash.

Best,

-Evil

[virtualreality69]

As per the subject really.

I have read in a few threads on this forum that users are recommending / using this motherboard for 4x GPU rigs, but nobody mentions doing anything special to get the GPUS detected.  I have tried the usual tricks of putting all 4 cards on powered risers and shorting the presence pins on the 16x slots and just about every combination of all this.

I have put together two small LTC mining rigs using identical parts and they both behave differently in terms of GPU detection, which is both very odd.

Both of the small rigs are:
ASRock 970 Extreme3 Rev2 -- 2x PCIE x16 Slots,  2x PCIE x1 Slots
Sempron 145 CPU --Yes I know this is crap and was a mistake :-)
4GB DDR3 1333mhz   cl9
1000W Fractal Tessla PSU

GPUs are Gigabyte R9 280x's

On rig#1 I can get a max of 3 GPUs working by plugging GPUs in to both x16 slots and the 3rd GPU into the 1x slot in between the two 16x slots using a powered riser.  A 4th GPU will not be detected if put into the remaining 1x slot on a powered riser.  I have tried all combinations and this is the max I can get detected on this one

On rig#2  I can only get a maximum of two GPUs detected!  Again I have tried all combinations of GPUs in slots / risers, presence pin shorts, etc and whats really odd is that if I put a GPU in each of the two 16x slots it only sees 1 GPU.  With GPUs in both the first x16 slot and the middle x1 slot I can get the two working and that's it :-(

Does anyone have any similar experience with these ASRock motherboards and ideally any tips or what do you all think I should do?  RMA them, get them swapped if possible maybe.  This motherboard is supposed to support both dual and quad crossfire.

A huge THANKS in advance for any direction on this one as I am really baffled by it and its really driving me nuts!  My gut is telling me that I should have just stuck with Intel when it comes to Mobos and CPUs, but I thought I would give this combo a bash.

Best,

-Evil

Mr. Evil... sorry Doctor Evil,
I also have the ASRock 970 Extreme3 and will be trying 3 GPU's shortly.  Currently I'm running a 7850, and I have 2 R9 270's on their way to me.  My goal is to try and run all 3 together for a bit before selling the 7850 and upgrading.

From what I've read 3 GPU's should work. However, knowing hardware and firmware related issues, its possible that you (and possibly myself) could have a bad combination somewhere.  I'd read up on it a little more and find out what you can.  My cards wont come in till Monday or Tuesday at the earliest. At that time I'll get back to you and let you know what happens on my end.

Cheers,
- VR

[virtualreality69]

I was able to get 2 asus R9 270's and my old XFX 7850 running on this board.  That being said, I'm having Loads of hardware errors on the one card thats on a pci riser cable.  Let me know if you have any questions. I'll respond faster to a PM than a post here, but feel free to do both.

This is the riser cable I got from Amazon. I choose it because it got multiple good reviews and was only around 15 bucks. Did I buy a shitty riser?


http://www.amazon.com/gp/product/B00HR1SWL4/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1


UPDATE:

I thought cgminer would order my GPU's vertically (from the top down), with the top most card being GPU 0, 2nd card (with the riser) being GPU 1, and the bottom card being GPU 2.  Looks like CGminer went from the bottom up. This woudlnt be a problem with the same GPU's, but my bottom card (R9 270) was getting the config for the 7850 which was causing issues.

Keywords: pci-e riser issues