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Topic: [.25 BTC Bounty] Cannot use more than 3 cards on GigaByte motherboard (Read 3643 times)

member
Activity: 86
Merit: 11
Odd problem indeed, do we have an answer yet?

I have the same Mobo short Risers ~ 15cm - 20cm ones do work with no problem here, i have 5 290 in one of my rigs.
I should mention that i made the powered cables myself.

Now when i use 30cm powered Risers i don't get to see a POST well sometimes it manages to show me a POST but that's it it hangs there.

It can not be a PSU problem but either cable or Mobo, i tested this with just one 290.
290 on board, works
290 on non powered 18cm Riser, works
290 on powered 18cm Riser, works
290 on powered 30cm Riser, no POST (tested with two different 30cm powered cables)

I even isolated my first self made powered risers with Aluminum Foil and on top some Isolation just to make sure i do not get interferences or magnetic fields build up but not seeing POST if i just use 1x30cm Riser cable on a Mobo with just 1 290 plugged in is pretty odd especially since my first rig is running now over a Month with 5x290 and my self made but short powered risers and yes i have been rebooting it quiet often.

legendary
Activity: 1361
Merit: 1003
Don`t panic! Organize!
Connect on 16x16 riser to  PCIEX16_1 and  PCIEX16_2
Connect on 1x16 riser to PCIEX4_1 and PCIEX4_2
Clean and reinstall drivers.
Try connecting CF bridge to x16 cards.
member
Activity: 112
Merit: 10
need more blower to make your machine still cool. Grin
hero member
Activity: 518
Merit: 500
So 'it did not work' but coincidentally the topic is suddenly dead. Don't want to pay the bounty?
hero member
Activity: 518
Merit: 500
Then I'll just post the 100% guaranteed to work solution:

Change your motherboards for Gigabyte 990FXA-GD65. Use presence mod on all 4 slots in 1x unpowered risers. Don't forget the motherboard's 6pin extra PCI-e power connector.
hero member
Activity: 991
Merit: 500
Did it work?

I am sorry but it did not work.

It's interesting to see miztaziggy have a similar problem.

What kind of cards are you using?

As I stated before, I have tried powered risers. No luck.

And it cannot be the OS because it doesn't even POST.

newbie
Activity: 24
Merit: 0
Powered risers?
Must have power beyond 3
member
Activity: 89
Merit: 100
To rule out OS or driver issues, have you tried another OS?
sr. member
Activity: 432
Merit: 500
I am having very similar issues with a Gigabyte 990 UD3.

With 3 cards directly to the 3 16x slots it works fine.

With 5 cards all plugged into 1x risers, only 4 cards get detected in Windows. That is with none of the slots shorted.

The card that isn't getting detected is the card plugged into second (middle) x16 slot. Both of the others and both of the 1x slot cards get detected and mine OK.

If I short the presence mod on the 1x slots it makes no difference.


If I short any of the x16 slots with the presence mod, the motherboard WILL NOT power on at all. As soon as I pull out the shorting wire, it powers on.

I will start a separate thread here with its own bounty:
https://bitcointalk.org/index.php?topic=387663.new#new
hero member
Activity: 518
Merit: 500
hero member
Activity: 991
Merit: 500
hero member
Activity: 518
Merit: 500
TDP is 275 for a R9 290, so the PSU has plenty of power.

I'm running 4 GPU's on my GigaByte motherboard. I use 1x risers on all cards.

What might be the key is running the presence mod on all PCI-e slots



It's what I needed to get my 4x GPU running and detected.

Otherwise, I can confirm that with the presence mod, the Gigabyte 990FXA-GD65 works on 4 GPU's (with some GPU's in the 1x slots, all slots on presence mod. Even the 16x slots). The GD65 also has the great extra power plug near the PCI-e slots.

Yes, you might not heed the a/b shorting mod with one card in the 1x slot and nothing for the rest, same with me. But with 4 cards, it was MANDATORY to do the mod on _all_ slots, even the 16x ones. Otherwise it did not work for me either.

I used thin paperclips bent into shape with some pliers.

Good luck, and look forward to the bounty.

1427iTKC5ygVBqeFjMj6YRkB9dtRnAgZA7

I have tried this. Shorting the 1x slot with a card on a 1x riser while the other 3 cards are plugged directly in. Same problem.

No POST. I also tried putting the HDMI cable in each card while booting.

Also some notes:

Booting the card from a 1x slot with a 1x riser with and without shorting the A/B pins works perfectly.

Just for shits 'n giggles, put them all on 1x risers and short all 4 slots?

I mean, at my Gigabyte board one card on a 1x riser in a 1x slot works fine too. All 4 at once caused the problem. Just try it mate.
hero member
Activity: 991
Merit: 500
TDP is 275 for a R9 290, so the PSU has plenty of power.

I'm running 4 GPU's on my GigaByte motherboard. I use 1x risers on all cards.

What might be the key is running the presence mod on all PCI-e slots



It's what I needed to get my 4x GPU running and detected.

Otherwise, I can confirm that with the presence mod, the Gigabyte 990FXA-GD65 works on 4 GPU's (with some GPU's in the 1x slots, all slots on presence mod. Even the 16x slots). The GD65 also has the great extra power plug near the PCI-e slots.

Yes, you might not heed the a/b shorting mod with one card in the 1x slot and nothing for the rest, same with me. But with 4 cards, it was MANDATORY to do the mod on _all_ slots, even the 16x ones. Otherwise it did not work for me either.

I used thin paperclips bent into shape with some pliers.

Good luck, and look forward to the bounty.

1427iTKC5ygVBqeFjMj6YRkB9dtRnAgZA7

I have tried this. Shorting the 1x slot with a card on a 1x riser while the other 3 cards are plugged directly in. Same problem.

No POST. I also tried putting the HDMI cable in each card while booting.

Also some notes:

Booting the card from a 1x slot with a 1x riser with and without shorting the A/B pins works perfectly.
hero member
Activity: 686
Merit: 500
Regardless, the cards should be detected when they're not in use.

If you use Linux, I can help.
hero member
Activity: 518
Merit: 500
We're all here to learn Smiley
member
Activity: 89
Merit: 100
1500W is the power it will provide on the 12v side. With 80% efficiency it'll draw about 1875 Watts from the socket.

Modern PSU's have no problem providing top power 100% of the time. My mining rigs are stable for many months at 24/7 100% PSU load (1200W on a 1250W Seasonic PSU).

Power is really not the issue. CPU doesn't draw 125 Watt either, as all you need is the cheapest dualcore you can find.

I stand corrected, thanks I didn't know it was measured on the 12v side.
hero member
Activity: 518
Merit: 500
According to this benchmark: http://www.techspot.com/review/736-amd-radeon-r9-290/page8.html, the R9 290 takes 350 watts.

Four cards would be 1400 Watts, add 125 watt for the cpu and the rest of the system and you're at 1525 Watt. A 1500 Watt PSU at 80% gives at most 1200 watts reliably, so perhaps one PSU wouldn't be enough to handle the load. However this is at 100% load, which it will never reach during POST sequence.



1500W is the power it will provide on the 12v side. With 80% efficiency it'll draw about 1875 Watts from the socket.

Modern PSU's have no problem providing top power 100% of the time. My mining rigs are stable for many months at 24/7 100% PSU load (1200W on a 1250W Seasonic PSU).

Power is really not the issue. CPU doesn't draw 125 Watt either, as all you need is the cheapest dualcore you can find.
member
Activity: 89
Merit: 100
According to this benchmark: http://www.techspot.com/review/736-amd-radeon-r9-290/page8.html, the R9 290 takes 350 watts.

Four cards would be 1400 Watts, add 125 watt for the cpu and the rest of the system and you're at 1525 Watt. A 1500 Watt PSU at 80% gives at most 1200 watts reliably, so perhaps one PSU wouldn't be enough to handle the load. However this is at 100% load, which it will never reach during POST sequence.

hero member
Activity: 518
Merit: 500
TDP is 275 for a R9 290, so the PSU has plenty of power.

I'm running 4 GPU's on my GigaByte motherboard. I use 1x risers on all cards.

What might be the key is running the presence mod on all PCI-e slots



It's what I needed to get my 4x GPU running and detected.

Otherwise, I can confirm that with the presence mod, the Gigabyte 990FXA-GD65 works on 4 GPU's (with some GPU's in the 1x slots, all slots on presence mod. Even the 16x slots). The GD65 also has the great extra power plug near the PCI-e slots.

Yes, you might not heed the a/b shorting mod with one card in the 1x slot and nothing for the rest, same with me. But with 4 cards, it was MANDATORY to do the mod on _all_ slots, even the 16x ones. Otherwise it did not work for me either.

I used thin paperclips bent into shape with some pliers.

Good luck, and look forward to the bounty.

1427iTKC5ygVBqeFjMj6YRkB9dtRnAgZA7
sr. member
Activity: 896
Merit: 272
Undeadbitcoiner Will not DIE until 1BTC=50K
Wouldn't 1500W be enough for 4 R9 290's? I used to run a full system with fans, 2 hdd's, 4x 7970s on an Enermax 1350W.

Also, I made powered risers. They work, but it's the same thing. I can't get 4 cards at once to work.

My board does not require shorting the a/b pins. The 1x riser works.


I run three R9 290x with 1200W PSU and I put the 4th card on 450W second PSU.
All four are on powered risers.  I'm using the same motherboard, default BIOS settings, Sempron 145 CPU, SSD drive.

!
+1

Did you tried changing motherboard? I dont thisk its issuee with PSU
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