Motherboard of choice for 6 or more GPU's

[ISAWHIM]

The only issue with 1x risers, is some only plug-in to a 1x slot. You have to cut-out the hole for the unnotched 16x slot. (Not difficult to do with a razor or dremmel.)

Some will say "fits 4x, 8x, 16x" (Those have one open end notched-out.)

16x has no advantage, even for litecoins. 1x is more than fast enough to send the tiny bit of data to be processed. 16x is only for sending massive GB of data, fast, over multiple lines, all at once.

I did notice that litecoins are real specific to having "balanced" memclocks/coreclocks. Something like a ratio of 0.53:1 to get ideal processing speed. More mem = slower, less mem = slower, just-right = max processing. (Adjust voltages to accommodate the core voltage that matches the mem clock/core clock ratio. That makes an issue for cgminer, as it uses a fixed-number, not a ratio, for adjusting clocks for speeds.)

If the G65 was as cheap as the G45, it would be worth it, in the long run. That would be one less motherboard along the way, as opposed to having 2-4 cards per motherboard. That is why I use the G45's. Two mobo's handle what others use three mobo's for. (That is less memory, less cpu's, less PSU's, and less wasted fan-cooling. Lower power, less heat, greater returns, faster returns.)

[p00chie]

I was able to detect 6 7850 cards with MSI Z77A-G45 win7 x64 but 2 of the have Code43 error. so it seems as if its a driver/os problem.

Used every slot except the 4th.

[ISAWHIM]

I was able to detect 6 7850 cards with MSI Z77A-G45 win7 x64 but 2 of the have Code43 error. so it seems as if its a driver/os problem.

Used every slot except the 4th.

If this is the G45... you need to put the monitor on the middle 16x slot/card... that is a "mobo" issue. (Also note, mining on that slot, will send a portion to the first 16x slot too??? Seen if you disable that card in CGminer, it shows as disabled/off but shows as mining about 5-2MHs when the other slot is also mining.) Might be because those slots turn into 8x/8x/4x with all 16x slots used. Thus, shared busses and bad programming of CGminer code.

The limitations comes from the bus hardware, which is why you can only put up to 7 active slots, and only up to 8-gpu cores. (They were not designed to put 8 video cards, they are 16-lanes short of a full 8 slots. Designated for PCI and ON-BOARD crap for motherboards, like network, usb, video, sound, etc. Not an issue for servers, but servers use dual processors, and they split the bus into two halves. Yet can still only take 8-GPU cores in software.)

ALSO NOTE: You can use MAPPING to "discover" unseen hardware in CGminer. But not if windows has disabled it. (That is a catalyst/windows issue, if you can not get them all seen beyond the motherboard thing above.)

Also try adding them one at a time... rebooting and discovering them one at a time.

[p00chie]

I was able to detect 6 7850 cards with MSI Z77A-G45 win7 x64 but 2 of the have Code43 error. so it seems as if its a driver/os problem.

Used every slot except the 4th.

If this is the G45... you need to put the monitor on the middle 16x slot/card... that is a "mobo" issue. (Also note, mining on that slot, will send a portion to the first 16x slot too??? Seen if you disable that card in CGminer, it shows as disabled/off but shows as mining about 5-2MHs when the other slot is also mining.) Might be because those slots turn into 8x/8x/4x with all 16x slots used. Thus, shared busses and bad programming of CGminer code.

The limitations comes from the bus hardware, which is why you can only put up to 7 active slots, and only up to 8-gpu cores. (They were not designed to put 8 video cards, they are 16-lanes short of a full 8 slots. Designated for PCI and ON-BOARD crap for motherboards, like network, usb, video, sound, etc. Not an issue for servers, but servers use dual processors, and they split the bus into two halves. Yet can still only take 8-GPU cores in software.)

ALSO NOTE: You can use MAPPING to "discover" unseen hardware in CGminer. But not if windows has disabled it. (That is a catalyst/windows issue, if you can not get them all seen beyond the motherboard thing above.)

Also try adding them one at a time... rebooting and discovering them one at a time.

Yea it is the G45.
My setup:

slot1 : 1x
slot2 : 16x: 16x-->1x
slot3 : 1x
slot4 :  not used
slot5 : 16x: 16x -->1x
slot6 : 1x
slot7 : 16x: 16x

No presence short on anything.

With this setup i can see 6 cards in win7 x64 and two of them have code43. So i cannot read anything from them with like gpu-z. Error cords are on cards in slot6 and slot7.

ATM i am using slot2 with monitor and slot 3 with dummy plug.

So you say i just can keep my setup and plug the monitor in slot5? And the dummy plug in which slot ?

[jaywaka2713]

I thought you couldnt use an x16 riser in an x1 slot

[p00chie]

I thought you couldnt use an x16 riser in an x1 slot

i don't do it.

i use 1x raiser in 16x slots.

Finally i was able to get 5 cards working with win7 and cat 12.6 + SDK

[CartmanSPC]

From what I've read here it looks like the MSI Z77A-GD65 with an Ivy Bridge CPU is the way to go for 7 GPUs. Up to 6 GPUs the MSI Z77A-G45 look to be the better choice if you don't mind having to presence short one of the slots.

There is about a $40 difference in price and you can use a slightly cheaper Sandy Bridge CPU with the G45.

Personally I think I may use a Z77A-GD65 with Ivy Bridge in my next rig even though I have a new 890FXA-GD70 set aside for it.
Will ANY Ivy Bridge CPU activate the 7th slot on the Z77A-GD65? Thinking of using the G1610. It's listed at 10 watts less than the G550 I have in my Z77A-G45.

Fun stuff

[ssateneth]

From what I've read here it looks like the MSI Z77A-GD65 with an Ivy Bridge CPU is the way to go for 7 GPUs

Do you have proof? Or are you just guessing? Screenshot with device manager and cgminer please.

[boozer]

Will ANY Ivy Bridge CPU activate the 7th slot on the Z77A-GD65? Thinking of using the G1610. It's listed at 10 watts less than the G550 I have in my Z77A-G45.

Fun stuff

I used the Celeron G1610 and I can use all 7 slots with it.

[ssateneth]

Will ANY Ivy Bridge CPU activate the 7th slot on the Z77A-GD65? Thinking of using the G1610. It's listed at 10 watts less than the G550 I have in my Z77A-G45.

Fun stuff

I used the Celeron G1610 and I can use all 7 slots with it.

Device manager and CGminer screenshots please.

[Toschi]

I have the Powercolor AX7950 GPUs with a 1600W LEPA PSU and the Gigabyte 990FX UD-5 motherboard. With a Kill-A-Watt hooked up to it, I see a power draw on it of about 1400W. Maybe that was when I had powertune at +20 on it though? I'm redoing that board now as we speak (bringing it up to Windows 8 instead of Windows 7) and won't be having powertune on it this next time. I'll report back once it is up and running. Swapping out standard risers for powered risers to see if the kH/s goes up some with non-powertuned settings. Then I'll attempt to add a 6th card into the PCI-e 1x slot (I have a 1x->x16 riser) if all goes well.

This milk crate is getting tight on space! :p

[jaywaka2713]

I have the Powercolor AX7950 GPUs with a 1600W LEPA PSU and the Gigabyte 990FX UD-5 motherboard. With a Kill-A-Watt hooked up to it, I see a power draw on it of about 1400W. Maybe that was when I had powertune at +20 on it though? I'm redoing that board now as we speak (bringing it up to Windows 8 instead of Windows 7) and won't be having powertune on it this next time. I'll report back once it is up and running. Swapping out standard risers for powered risers to see if the kH/s goes up some with non-powertuned settings. Then I'll attempt to add a 6th card into the PCI-e 1x slot (I have a 1x->x16 riser) if all goes well.

This milk crate is getting tight on space! :p

I highly advise against using Windows 8. Setting up AMD Drivers on Windows 8 was hell for me and my friends on various systems. We couldn't get it to recognize 3 7950s on one system and we tried the 11.12, 12.8, 13.1, and 13.4 drivers and every time it just jacked the display and didnt work each time. We probably missed something required, but we reverted to W7 and Linux on the systems and they work fine.

Powered risers will ensure that you have the highest possible hashrate though when using a motherboard with more than 4 GPUs. My friends do out safety reasons though (fire prevention).

[marvel212]

To run six cards on this board (at least for scrypt mining), wouldn't you need two PSUs connected to get past the 1600W max PSU size you can buy to feed them? Or just get all undervolted cards on there? Would powered risers be needed if you undervolt the cards or no?

I would use powered risers regardless just for the sake of not frying the motherboard. It also ensures you are getting the max hashpower possible, while protecting peace of mind 

Doesn't power risers matter with older cards.  With current 7xxx series it pulls so little watts off the PCI-E slot.

[jaywaka2713]

To run six cards on this board (at least for scrypt mining), wouldn't you need two PSUs connected to get past the 1600W max PSU size you can buy to feed them? Or just get all undervolted cards on there? Would powered risers be needed if you undervolt the cards or no?

I would use powered risers regardless just for the sake of not frying the motherboard. It also ensures you are getting the max hashpower possible, while protecting peace of mind 

Doesn't power risers matter with older cards.  With current 7xxx series it pulls so little watts off the PCI-E slot.

Powered risers are good for the older cards for sure. However it isnt the card series we are talking about. These motherboards weren't designed to support 7 GPUs, and because of that, the power draw cannot be fulfilled by the motherboard when overclocking or running the 7 cards in general. It prevents issues with frying the motherboard too. With x16 slots, you usually dont need powered risers (The 7990 cards do though), but the x1 to x16 risers need to be powered because the x1 slot simply doesn't output enough energy.

[marvel212]

To run six cards on this board (at least for scrypt mining), wouldn't you need two PSUs connected to get past the 1600W max PSU size you can buy to feed them? Or just get all undervolted cards on there? Would powered risers be needed if you undervolt the cards or no?

I would use powered risers regardless just for the sake of not frying the motherboard. It also ensures you are getting the max hashpower possible, while protecting peace of mind 

Doesn't power risers matter with older cards.  With current 7xxx series it pulls so little watts off the PCI-E slot.

Powered risers are good for the older cards for sure. However it isnt the card series we are talking about. These motherboards weren't designed to support 7 GPUs, and because of that, the power draw cannot be fulfilled by the motherboard when overclocking or running the 7 cards in general. It prevents issues with frying the motherboard too. With x16 slots, you usually dont need powered risers (The 7990 cards do though), but the x1 to x16 risers need to be powered because the x1 slot simply doesn't output enough energy.

From what I researched PCIE x1 slots output 25watts and from what I gather 7xxx series card use less than 15 watts off the slot.

[ssateneth]

Not sure why "powered risers" and "hashrate" are in the same sentence in so many posts. Show me proof that powered risers remotely affect hashrate. I have 53 individual GPU cores all mining and not a SINGLE riser is powered. 666.2 MHash off a single 7970 at 1110/170 (Undervolted, can do 732.2 mhash at 1220 core stock volts), 408.3 mhash off a single 5870 at 880/176 (undervolted), single 5970 core @ 800/160 pushing 371.1 mhash (also undervolted), and so on.

[Beaflag VonRathburg]

For 6 GPUs, I prefer the Z77A-GD65.  No presence pins need shorted, there are power buttons on the MB, and there's a 2 digit POST debug readout.  Technically you could run 7 cards on this MB with the right processor (the bottom slot is only active when an Ivy Bridge CPU is installed).

I have 9 of these rigs running with six 7950s each.  No powered risers, 1040-1070mhz per card, and 300mhz ram clocks.  They're stable.

https://i.imgur.com/2feHArIl.jpg

https://i.imgur.com/2feHArI.jpg

I purchased this board because of your comment. I currently have it working with 7 GPUs and a G1610 ivy bridge cpu. I did have to short the bottom two 16x slots with 1x risers.

From what I've read here it looks like the MSI Z77A-GD65 with an Ivy Bridge CPU is the way to go for 7 GPUs. Up to 6 GPUs the MSI Z77A-G45 look to be the better choice if you don't mind having to presence short one of the slots.

There is about a $40 difference in price and you can use a slightly cheaper Sandy Bridge CPU with the G45.

Personally I think I may use a Z77A-GD65 with Ivy Bridge in my next rig even though I have a new 890FXA-GD70 set aside for it.
Will ANY Ivy Bridge CPU activate the 7th slot on the Z77A-GD65? Thinking of using the G1610. It's listed at 10 watts less than the G550 I have in my Z77A-G45.

Fun stuff

See above.

Not sure why "powered risers" and "hashrate" are in the same sentence in so many posts. Show me proof that powered risers remotely affect hashrate. I have 53 individual GPU cores all mining and not a SINGLE riser is powered. 666.2 MHash off a single 7970 at 1110/170 (Undervolted, can do 732.2 mhash at 1220 core stock volts), 408.3 mhash off a single 5870 at 880/176 (undervolted), single 5970 core @ 800/160 pushing 371.1 mhash (also undervolted), and so on.

How many cards are in the system and what OS are you using? I've found that with Windows 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 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.

[YipYip]

Not sure why "powered risers" and "hashrate" are in the same sentence in so many posts. Show me proof that powered risers remotely affect hashrate. I have 53 individual GPU cores all mining and not a SINGLE riser is powered. 666.2 MHash off a single 7970 at 1110/170 (Undervolted, can do 732.2 mhash at 1220 core stock volts), 408.3 mhash off a single 5870 at 880/176 (undervolted), single 5970 core @ 800/160 pushing 371.1 mhash (also undervolted), and so on.

I assume you are mining BTC from previous posts and ltc\scrypt has major power issues compared to BTC in relation to risers and power...

I have 2 burnt out mobo's and 3 burnt out PSU ATX connectors from NOT using powered risers in rigs with 4+ cards ...also even on spin up the cards WITH powered risers are more stable and always 1-4 hash above the rest

i.e
gpu 0  620  (non)
gpu 1 622 (powered)
gpu 2 619 (non )
gpu 3 622 (powered)
gpu 4 620 (non)

I am speaking purely from results and xp..i could send a video showing the spin up with powered and non powered on the same rig\gpu's ...if needed

[ssateneth]

blah blah, picture with 7 video cards

Can you show me your device manager and cgminer screenshot to show all 7 gpu mining please

[Beaflag VonRathburg]

blah blah, picture with 7 video cards

Can you show me your device manager and cgminer screenshot to show all 7 gpu mining please

Done.


Please answer:

Not sure why "powered risers" and "hashrate" are in the same sentence in so many posts. Show me proof that powered risers remotely affect hashrate. I have 53 individual GPU cores all mining and not a SINGLE riser is powered. 666.2 MHash off a single 7970 at 1110/170 (Undervolted, can do 732.2 mhash at 1220 core stock volts), 408.3 mhash off a single 5870 at 880/176 (undervolted), single 5970 core @ 800/160 pushing 371.1 mhash (also undervolted), and so on.

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.