4x 280x mining rig on Asrock 970ex4, windows 7 doesn't detect gpus

[Pompobit]

Hi,

I'm trying to let windows 7 32bit to detect all my 4 gpus (2x vapor-x 280x and 2x asus directCUII TOP 280x) with no luck.

I'm using 3x powered riser cables (1x to 16x) and 1 gpu directly attached to the motherboard (ASrock 970 extreme 4).

All I can get is having two cards detected, sometimes a get a third but windows sees it as a HD7900  Huh
I've no jumped the pins because I heard my mobo doesn't need that, but probably I'll give it a try...

Should not be a power issue, the risers are powered and my psu should be enough (1300W coolermaster gold)

Anyone with a similar configuration/mobo/gpus?

Which pins you used? With the dummy plugs?

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[nnay_th]

Hi mate,

I have the same GPUs and same motherboard. After struggling for days wondering how to get my cards detected on riser, I found out that it was due to faulty risers.

Now they are detected, and for info they are connected as follow:
First PCIe 1x --> Powered riser 1x to 16x
First PCIe 16x --> Unpowered riser 16x to 16x
Second PCIe 1x --> Powered riser 1x to 16x
Second PCIe 16x --> Does not detect GPU in this setting (I wonder why)
Third PCIe 16x --> Powered riser 1x to 16x

No dummy plug. Only difference is taht i use Windows 7 x64. I don't know if there would be a difference with x32 though...

Now that they are detected, I can run cgminer with the four GPUs, however I have stability issue. The rig crashes and reboot randomly (less than one hour continuous mining), but I keep looking on some solution.

I did not have stability issue with 3 GPUs.

Hope it helps.

[Pompobit]

Thank you for the help,
 but I figured today myself that the issue was due to faulty risers also in my case...

I bought 4 powered 1x to 16x cables and two of them don't work properly... Plugging 2 gpus directly on the 16x slots and the remaining two with the working risers did the trick and now windows 7 detects all gpus correctly.

Seems a lot of risers cables sold nowadays are of poor quality and many people reports problems.


If can I say something about your rig's instability, could be due to lack of power, maybe your psu is not enough for 4 gpus? You should have at least a 1200w gold rated psu, with a 1250-1300w gold would be safer.

Btw thank you again for your response

[ihopeigetrichpls]

Thank you for the help,
 but I figured today myself that the issue was due to faulty risers also in my case...

I bought 4 powered 1x to 16x cables and two of them don't work properly... Plugging 2 gpus directly on the 16x slots and the remaining two with the working risers did the trick and now windows 7 detects all gpus correctly.

Seems a lot of risers cables sold nowadays are of poor quality and many people reports problems.


If can I say something about your rig's instability, could be due to lack of power, maybe your psu is not enough for 4 gpus? You should have at least a 1200w gold rated psu, with a 1250-1300w gold would be safer.

Btw thank you again for your response

hi where did you buy the working risers?

so others can make sure to stay away from the bad ones

[nnay_th]

Thank you for the help,
 but I figured today myself that the issue was due to faulty risers also in my case...

I bought 4 powered 1x to 16x cables and two of them don't work properly... Plugging 2 gpus directly on the 16x slots and the remaining two with the working risers did the trick and now windows 7 detects all gpus correctly.

Seems a lot of risers cables sold nowadays are of poor quality and many people reports problems.


If can I say something about your rig's instability, could be due to lack of power, maybe your psu is not enough for 4 gpus? You should have at least a 1200w gold rated psu, with a 1250-1300w gold would be safer.

Btw thank you again for your response

Yeah, I suppose the demand is so big that they make them in a haste and don't bother with quality control...

As for the instability, I am not sure about the lack of power as I have 2x 850W 82% efficiency PSU... two cards on each PSU. But I may try to add a third one, as it seems that one PSU runs hotter than the other.

I installed the latest AMD drivers (13.12), and it seemed to have resolved the problem... until this morning. It was hashing for 7 hours straight then started rebooting every now and then (less than an hour each time)

Thank you for the help,
 but I figured today myself that the issue was due to faulty risers also in my case...

I bought 4 powered 1x to 16x cables and two of them don't work properly... Plugging 2 gpus directly on the 16x slots and the remaining two with the working risers did the trick and now windows 7 detects all gpus correctly.

Seems a lot of risers cables sold nowadays are of poor quality and many people reports problems.


If can I say something about your rig's instability, could be due to lack of power, maybe your psu is not enough for 4 gpus? You should have at least a 1200w gold rated psu, with a 1250-1300w gold would be safer.

Btw thank you again for your response

hi where did you buy the working risers?

so others can make sure to stay away from the bad ones

I got mine on ebay.

But with all the issues with poor quality risers, I am more than willing to pay for a premium if a big and reliable company would sell those at their standard quality.

[spartan82]

I have yet to test these myself but there has been a lot of good feedback on the new USB style powered risers. They only come in the 1x to 16x.. Should receive mine next week sometime, cant wait to test them out

[Pompobit]

also my risers were bought on ebay, but the seller seems inclined to pay a refund. Let's see

[madjules007]

I am having the same issue with my Asrock Z77 Extreme 6 and 4 x (Sapphire) 280x's.

On three cards on three x16 - x16 unpowered risers it works just fine. When I add the 4th card to the 1x slot with a 1x -16x powered riser, the card doesn't work properly. It usually does get detected, but mostly with an error code in the device manager (code 43, code 31, code 10), which makes it unusable. When it DOES work it is very unstable.

Yesterday I received a new riser cable. This time, the card gets detected as a 7900 and also still gives error code 43.

I have more risers to test, but I really don't think the problem has to do with the risers (in my case), more with the AsRock motherboard. I am yet to find a solution for this problem. I have heard other people have this problem too with this motherboard.

I am really waiting for a definitive answer that a pci-e jumper might do the trick, but I can't find ANYONE who has this problem and who could actually solve it, with this motherboard.

[Telek]

I've been fiddling with risers as well, and as far as I can tell it's more a motherboard problem.

For example on ASUS motherboards they very rarely like the 30cm risers, but can usually handle the 15cm risers.  However the exact same 30cm riser and card on an MSI motherboard works perfectly fine.  I have an older ASUS P5Q-E motherboard with 5 slots, and only two of them like the 15cm risers, the rest refuse to work.  There are three on-board x16 slots, and all three can run a card no problem, so it's not the card or the motherboard directly.

I've tried risers in all configurations - completely unpowered (and no cap), unpowered (with cap) (as in the molex is there, just unused), powered (molex attached) and cut (molex attached).  Doesn't seem to make a difference to this motherboard.

I suspect the BIOS and/or motherboards have different thresholds for detecting the cards, and since risers drastically increase the line length you have slightly different timings.  If the BIOS/mobo isn't versatile enough to handle that it just won't detect the card, or it may work flakey.

Other people have mentioned that if your BIOS has settings to force the PCIe slots to v1.0 or v2.0 mode then risers tend to work more reliably, however my BIOSes don't seem to have that option.

[nnay_th]

How about USB3 style risers? They seem to be more and more popular. I haven't tried them myself though