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Hi everyone,

I can't connect 6 GPUs (Asus r9 290) to my motherboard MSI Z77A-G45.

I read these posts: https://bitcointalk.org/index.php?PHPSESSID=nbigpv5ko1uc856pi2et7jjpj1&topic=102547.msg1124000#msg1124000 and https://bitcointalk.org/index.php?topic=142241.msg1515460#msg1515460
and I know that it is possible to run 6 GPUs on that mobo.

Linux (ubuntu) can see max 5x cards when I short two middle x1 slots (http://pl.tinypic.com/view.php?pic=2qn48ip&s=8),  PCI-E pins like that https://ip.bitcointalk.org/?u=http%3A%2F%2Fblog.zorinaq.com%2Fimages%2Fpcie-short-schematic.png&t=536&c=8DJ_1hJYAKw0Ag


Hardware:
6gb DDR3
Intel G1610
3x PSU Corsair 750 W 80+gold


Could you help me to solve the problem?

Thank you in advance

You need to only short slot number 5.  Then don't use slot number 4 as it deactivates.  Use slots 1,2,3,5,6,7  1x risers must be used on all slots.

It works!

Linux sees now 6 GPU, but when I install Multiminer, it can see only one GPU ;c

Glad you got it workin :)  Not sure about multiminer, maybe someone else can chime in 8)

Have you tried CGMiner?

I installed cgminer today

Now it works perfectly :)


Mobo for 6 gpu for 100-120 usd, great :D

tsg (or Gazza1),

what are your settings in bios?  I have the same motherboard and cards but I can't get past bios with cards on my risers.  Right now I have a 1x-16x powered riser in slot 2 and a 1x-16x powered riser in slot 5.  Slot 5 is shorted.  I can see the bios screen but it is off center and the text is all messed up and there are artifacts everywhere.  Then windows tries to start and crashes. 

nI can get to windows with 2 cards on risers in slot 2 and 5 (shorted) with 4x-16x risers.  But Nothing else works, if I try to install a 3rd card on a 1x-16 riser or exchange one of the 4x-16x risers for a 1x-16x riser I can't make it past bios. 

Any ideas?  Could my 1x-16x risers be bad?

Thanks in advance.

I have my BIOS at default.  To test the risers I would try each one individually on slot 2.  I have in the past noticed weird behavior on getting GPUs noticed.  I have always found the best success to use the slots in this order if running less than 5 cards.  2,1,7,6,3, & 5 last with 5 being the only shorted slot and to be used for the 6th card.  I also use 1x risers on everything, I can't say for sure on this mobo, but some mobos have issues supplying the bandwidth with larger risers.

Also artifacts are often a clock/voltage issue, have you overclocked or undervolted?

I haven't overclocked or undervolted the system or any cards.  It was a clean install, I got 3 cards stable seated on the motherboard then started trying with the risers.  The only time I get the artifacts is with the 1x risers, the 4x(they're actually 8x) risers work just fine, and if I remember right I don't even get to the bios with a 16x riser.  I have checked each riser in a different motherboard and they all worked but I'll double check.  I have an identical motherboard so that will help.  (On a side note, the machine that I checked the risers on will now only see a pci-e card with a 1x-16x riser, doesn't even work if seated on it.)

I guess since you left your z77a bios at default you never messed with turning off pci-e 3  the pci latency.  I probably should have asked this a long time ago but do I need to short slot 5 if no card/riser is in there?  It seemed to help but I'll test that too.  Thanks for helping.

Na slot 5 only needs shorting if there is a card in it.  Yeah my BIOS were bone stock default.

Which Catalyst version do you use to get 6 cards working?

So I tested all my risers and found that the only ones that work reliably are the 8x-16x.  The others don't work at all.  With the 1x-16x I get artifacts and windows cannot boot.  With the 16x-16x I can't even get to bios, the screen just stays black.  I had an older nvidia card laying around so I tested it and it worked with all the risers.  I'm going to now test a 5770 but I have a feeling it's going to work also.  Somehow I think my r9 s are not compatible with my risers.  I thought it could be my psu (corsair ax1200) but it works great when no risers are involved and it has good reviews.

Anyone got any ideas?

btw Gazza1, are you using r9 s in your z77?

Yes I have a few of those mobos that are running 6 cards each, one has 6x sapphire 280x.  using all 1x powered risers.  It sounds like the 1x risers you have may be damaged.  

Risers are a nightmare, you will need powered definatley! I can only run 4 without powered as it's a quad x-fire board

jch9678 I'm using 3x 1x1 risers (19,5cm), 1 riser 16x16 (19,2 cm. Riser 16x16 is needed in the middle 16x slot) and 2 risers 1x1 (30cm)


SHORTING SLOTS IS NOT NECESSARY.
Bios settings -> DEFAULT


Slots:
-1 (1x1)
-2 (1x1)
-3 (1x1)
-4 (empty)
-5 (16x16)
-6 (1x1)
-7 (1x1)


So 6 cards works well! :)

Show us picture.  That makes sense though, the x16 providing the presence needed on that slot.  Very interesting.  :D  I bet a x4 would work too then.

wtf, I couldn't get more than 3 cards to work on these motherboards no matter what I tried. Different xubuntu versions, different driver versions. Total pain. OP what xubuntu and amd drivers are you running?

My risers work fine on the board, I just could only use 3 at a time, adding a fourth made the computer fail to boot.

Your mobo must have been defective.  I've run 5 on handfuls of different drivers on win7, win8.  Win8 runs 6 with special driver mod.  Linux will run the 6 out of the box.

I've got three of them. Tried it on all three. Each has a celeron G1610, 4gb ram, xubuntu 12.10 or 13.04 (also tried bamt 1.3) running from usb drives. Cards on risers, because you can only run three cards on the motherboard without risers. Risers and gpus are all known good. The boards just don't boot when I have more than three cards plugged in.

Pop in another stick of ram, for 8GB.  Now that you mention it, I was never able to run more than 3 cards with 4GB either.

Tried that, also monitoring through htop. Never even gets close to using 4gb of ram, and that wouldn't matter on boot. The motherboards won't even start.

Weird.  I've got a few of those boards running 6 cards each.  RAM usage never goes above 4, but the system allocates 7.9GB with 6 cards if you watch with RAMmap or an in depth ram watcher.

None of my other rigs with 5-6 cards use more than 2-3 gb (none of them have more than 4gb installed). I've never had one of these msi boards start up with more than 3 cards plugged in, so I can't monitor that.

It's not a big deal, I took them out of the racks and they just run their three cards in the pc case and heat up my downstairs rooms.

I assume you're monitoring with a program other than taskmanager?  Because task manager doesn't show it.

Which cards are you using on the other rigs? 

htop, I'm running linux not windows.

RickJamesBTC, did you ever try running windows to see if that works.  Just curious because I may be in the same situation as you except I'm running windows 8.1 with 8GB of Ram.  I just bought 2 of your usb risers to test and they get delivered today.  At least I know your risers worked for you. 

Someone told me he had trouble with some long ribbon risers and 290s.  My 8x-16x risers work, they are ~17cm and have 2 capacitors but my 1x-16x risers are 30cm and have only 1 capacitor.  I thought the extra capacitor might be reducing the extra 'noise' the 290s introduce (speculation) or the length could be the problem?  Although all the risers work just fine on a test motherboard.  Very weird.  I had to order the long USB risers from you because that was all that was left in stock, has anyone reported trouble with the risers due to length? 

Long shot, but do you run a Corsair AX1200 or an Antec HCG 900?  I noticed in your thread about the risers someone was having trouble with that Corsair.

Gazza1, is this the modified driver you are talking about?  https://litecointalk.org/index.php?topic=11761.0

The USB risers work at quite a long length. I've got some on 10' cables. Some on 6' cables. All work fine.

I have no interest in running windows on my machines. I have far too many rigs to bother with those installations.

Power supply has zero effect on the performance of cards, as long as there is enough power available for your system it will be fine.

Thanks

Ah good to hear. 

I was thinking the power supply may have an effect on the risers using the molex connection.  I'm just speculating about my problem. 

Looking forward to trying your risers.

6 gpus are possible and not really hard. I've just built another rig on that motherboard (6x r9 270x).

The key is Linux and using 16x16 riser (Maybe x4 would work too, but I had only x16 ;) )