Motherboard of choice for 6 or more GPU's

[madkind]

It seems I've just picked my next mobo, thanks for the pictures Beaflag.

[YipYip]

It seems I've just picked my next mobo, thanks for the pictures Beaflag.

That is awsome.... I just bought one of those boards last week so pretty happy

Also i think its official..the ZA77 GD 65 is mobo of the month

[CartmanSPC]

LOL, hope this doesn't cause the price to go up on the GD65 

Still in the process of designing/building a case but will eventually try to push seven 7970's on this MB.

Restraining myself from buying the MB and additional cards now.

[ssateneth]

Damn, I misunderstood you. I thought you were using Z77A-G45 and magically got  7 GPU working, but you in fact used the Z77A-GD65. The G45 has a limitation where if PCI_E4 is populated, PCI_E3 is turned off in the manual. The G65 does not say this though, probably due to the fact that the furthest PCI-E 16x slot is driven by the CPU (noted by the PCI-E 3.0 compliance) and not the chipset. So the cheapest, TRUE 7 GPU board is the GD65.

Did you know this before you bought the GD65 instead of the G45?

How many cards are in the system, what OS, and catalyst drivers are you using? I've found that with Windows machines every card I add drops the hashrate of the other cards. Example. I have two 7970s in my desktop set at 1094mv, 1080e, 170m and they get 645mh each. One of my rigs has four 7970s and at the exact same settings those cards get 612mh each. I've had this issue since using 11.12, 12.6, 12.8, 13.1, and 13.3.

[/quote]

As far as I know, I have not detected any drops in hashrate with as many cards as I am using. Many of my systems are 6 cards and 8 GPU (some are dual gpu). 5870's and 5970's. I run them all at 1 volt and core frequencies vary greatly depending on core quality and power quality. 5970's have less phases than 5870's so I usually get lower core clocks on a 5970 core versus a 5870. My 5970 cores vary from 735-860 at 1 volt, and 5870 cores vary from 775-905 at 1 volt. The core speeds sit right on the edge of causing a driver crash, within 5 MHz. I get about 0.46673 MHash per MHz on 5870/5970's. I use 11.12 driver and 2.1 SDK (Install 2.1 SDK after you install 11.12 + 2.6 SDK and have rebooted, select platform #1 in cgminer), phatk, vectors 2, worksize 128, 1:5 memory to core ratio, intensity 10.

Some of my rigs I've needed to mix 7970 and 5xxx. This is very unoptimum for the 5xxx cards as they will run about 5-10% slower with the newer SDK, and the newer driver required to drive the 7970's the fastest don't support 2.1 SDK installed along side. I opt to using 12.6 drivers, SDK from 13.1, diablo kernel, vectors 1 for 7970 and 2 for 5xxx, worksize 128, low memory, and intensity 10 for 5xxx, 11 for 7970.

[FullLife]

I'm surprised that with all this talk of the Z77A-G45 and Z77A-GD65 boards that no one has mentioned the Z77A-GD55 board.  I bought this board instead of the G45 board b/c I wanted the power and reset buttons and I'll gladly pay an extra $15 for those features.  This board seems to be almost identical to the GD65 board.  The only differences I can see is the GD65 has a slightly newer audio chip and (3) PCI-e 3.0 x16 slots vs the GD55's (2) PCI-e 3.0 x16 slots and 1 PCI-e 2.0 x16 slot.  I really don't think that will matter since PCI-e bandwidth is not an issue.

I don't have enough cards right now to see how many it will run, but they're on order.

[Beaflag VonRathburg]

Damn, I misunderstood you. I thought you were using Z77A-G45 and magically got  7 GPU working, but you in fact used the Z77A-GD65. The G45 has a limitation where if PCI_E4 is populated, PCI_E3 is turned off in the manual. The G65 does not say this though, probably due to the fact that the furthest PCI-E 16x slot is driven by the CPU (noted by the PCI-E 3.0 compliance) and not the chipset. So the cheapest, TRUE 7 GPU board is the GD65.

Did you know this before you bought the GD65 instead of the G45?

How many cards are in the system, what OS, and catalyst drivers are you using? I've found that with Windows machines every card I add drops the hashrate of the other cards. Example. I have two 7970s in my desktop set at 1094mv, 1080e, 170m and they get 645mh each. One of my rigs has four 7970s and at the exact same settings those cards get 612mh each. I've had this issue since using 11.12, 12.6, 12.8, 13.1, and 13.3.

As far as I know, I have not detected any drops in hashrate with as many cards as I am using. Many of my systems are 6 cards and 8 GPU (some are dual gpu). 5870's and 5970's. I run them all at 1 volt and core frequencies vary greatly depending on core quality and power quality. 5970's have less phases than 5870's so I usually get lower core clocks on a 5970 core versus a 5870. My 5970 cores vary from 735-860 at 1 volt, and 5870 cores vary from 775-905 at 1 volt. The core speeds sit right on the edge of causing a driver crash, within 5 MHz. I get about 0.46673 MHash per MHz on 5870/5970's. I use 11.12 driver and 2.1 SDK (Install 2.1 SDK after you install 11.12 + 2.6 SDK and have rebooted, select platform #1 in cgminer), phatk, vectors 2, worksize 128, 1:5 memory to core ratio, intensity 10.

Some of my rigs I've needed to mix 7970 and 5xxx. This is very unoptimum for the 5xxx cards as they will run about 5-10% slower with the newer SDK, and the newer driver required to drive the 7970's the fastest don't support 2.1 SDK installed along side. I opt to using 12.6 drivers, SDK from 13.1, diablo kernel, vectors 1 for 7970 and 2 for 5xxx, worksize 128, low memory, and intensity 10 for 5xxx, 11 for 7970.

I had previously read your post about the GD45 and the above quoted member about the GD65. Originally, I didn't want to have to jumper anything. I only had two extra risers with more on order so I had the seven cards split across two rigs. When, I went to combine them into one I noticed the only slots that weren't detecting with risers were the full 16x slots. The issue was that I knew they previously worked as I had cards populated onboard in those slots before I combined the rigs. With that I decided to test a jumper cable on the bottom two 16x slots and it detected as soon as I started the machine it detected the extra GPUs without issue.

All of my rigs have the same type of cards in them:

2*7970s
4*7970s
4*7870s
3*6950s
7*5870s

I've noticed across every single one that the more cards I add each card loses a small amount of performance. I know it isn't power related as each system has 1000-1200 watts of 80+ gold PSU so the only thing I can figure is that it is something with the software. The first rigs I ever build were 4x5870 machines. Each card got 435mh at 950/170 with xubuntu 11.04, catalyst 11.6, and sdk 2.6. Recently, when I had to split my 5870s into two rigs. One was a windows 7 machine with 5 cards and the second an 11.04 machine with the same software listed above. Even after 16 months and completely different hardware those settings got me the exact same 435mh / card in linux, but with only 2 cards in the system versus 4. I know it has something to do with Windows 7 and I really wish I could figure out what the issue is.

Quickly adjust my desktop with 2x7970s from poclbm and worksize 64 to diablo and 128 picked up 4 MH / card. I'll give that a test on the 4x7970 rig to see if that makes a difference in the aggregate card issue.

[CJM1682]

so will i need to short anything if i get the GD65 with an ivy cpu? i will start with 5 GPU's upgrading to 6 then 7 shortly. current makeup will be all 5 via powered risers. 3 are 16x -> 16x and the other 2 are 1x - 16x. does anyone foresee a problem?? Also will any of this differ if i get the GD65 Gaming series?

[jaywaka2713]

LOL, hope this doesn't cause the price to go up on the GD65 

Still in the process of designing/building a case but will eventually try to push seven 7970's on this MB.

Restraining myself from buying the MB and additional cards now.

I read somewhere that companies like NewEgg actually watch these boards closely.

[thecryptokeeper]

I can confirm that you don't need to do a short on the GD65. I had to use Windows 8 to kick in the sixth GPU.

https://i.imgur.com/nfkzeH3l.jpg

https://i.imgur.com/QeSPawZl.png?1

[thedonvon]

I have the z77a-gd65 and i cannot get 5 cards to run.  I have tried all different combinations of slots and i always have 1 card which shows up in windows but has a code 43 problem.  Can someone please help i want to get 5 cards running on this board.  Then hopefully 6!  I am runing 7950s with win7 enterprise x64.  Please help!!!!  Thanks so much

[CartmanSPC]

I have the z77a-gd65 and i cannot get 5 cards to run...always have 1 card which shows up in windows but has a code 43 problem...with win7 enterprise x64.

Try Windows 8. Seriously...it has been reported to support more cards.

[cptmooseinc]

I have Windows 8 and can confirm at LEAST 5 cards run on it with no problem.

[CartmanSPC]

I can confirm that you don't need to do a short on the GD65. I had to use Windows 8 to kick in the sixth GPU.

Nice setup! You don't have problems with cooling? Are those 7950's or 7970's?

[thecryptokeeper]

They are MSI TW3 7950's. I believe my cooling is sufficient. However, I think I need to replace the TIM on some of them to get better cooling.
Check this out for more details of my rig https://bitcointalk.org/index.php?topic=7216.msg2220732#msg2220732

I can confirm that you don't need to do a short on the GD65. I had to use Windows 8 to kick in the sixth GPU.

https://i.imgur.com/nfkzeH3l.jpg

Nice setup! You don't have problems with cooling? Are those 7950's or 7970's?

[thedonvon]

Ok i have installed windows 8 and all the cards are recognized without any errors.  Has any1 experienced problems with cgminer on win8?  I cant get it to run with my config file.  Very weird it keeps crashing and saying "cgminer has stopped working"

[Beaflag VonRathburg]

Ok i have installed windows 8 and all the cards are recognized without any errors.  Has any1 experienced problems with cgminer on win8?  I cant get it to run with my config file.  Very weird it keeps crashing and saying "cgminer has stopped working"

It is a stability issue with your config. I've had the same issue before. You have to go in and change some settings to make it stable again. It is different for every rig.

[thedonvon]

Ok i have installed windows 8 and all the cards are recognized without any errors.  Has any1 experienced problems with cgminer on win8?  I cant get it to run with my config file.  Very weird it keeps crashing and saying "cgminer has stopped working"

It is a stability issue with your config. I've had the same issue before. You have to go in and change some settings to make it stable again. It is different for every rig.

I even tried running my config without any parameters and it didnt work.  It will run if i remove the --scrypt.  It is the --scrypt that is causing the problem.  Not sure how to fix this??

[CJM1682]

uninstall catalyst control remove all.

boot into safe mode and with driver fusion remove amd graphics drivers completely.

run cccleaner and clean up all registry errors

install catalyst 12.8 and SDK 2.7.

this fixed the problems i had with this same cgminer issue

[jaywaka2713]

I have the z77a-gd65 and i cannot get 5 cards to run...always have 1 card which shows up in windows but has a code 43 problem...with win7 enterprise x64.

Try Windows 8. Seriously...it has been reported to support more cards.

I've only heard issues regarding Windows 8. My friends and I couldnt get the G45 board to accept 5 cards on it and we even used presence shorts.

[thedonvon]

I have the z77a-gd65 and i cannot get 5 cards to run...always have 1 card which shows up in windows but has a code 43 problem...with win7 enterprise x64.

Try Windows 8. Seriously...it has been reported to support more cards.

I've only heard issues regarding Windows 8. My friends and I couldnt get the G45 board to accept 5 cards on it and we even used presence shorts.

Well i got it to recognize all 5 cards without errors but now i cant get cgminer to run.  I am going to try and do a complete uninstall and try catalyst 13.1 instead of 13.4.  I will let you know how it works