I want to build a 5 GPU rig, but don't know how.

[jaywaka2713]

So I want to build a 5 GPU rig for enthusiast Bitcoin mining. I've always come to know motherboards that only accept 4 GPUs, but have seen rigs that have 5, 6, or even 7 GPUs, and I'm literally lost with how that works. I know one requirement I have is to use an i7 Ivy Bridge (might wait for Ivy Bridge-E processors this year) for the PCIe 3.0 support. However, does the 3.0 technology even carry an advantage over the 2.0/2.1 in terms of hashpower? I want to run 7950 overclocked cards on the rig too. I know I will need a 1600W PSU. So I am coming here to have all the details explained in terms of what motherboards are good candidates for a 5 GPU setup, what additional supplies I will need, and set up details and limitations. All information that can be given will be accepted. Money isn't a limitation. I will also be running the system headless with Debian Linux. I plan on using 8 GB of RAM too.

[notaek]

I would recommend the MSI Z77a-G45: http://www.newegg.com/Product/Product.aspx?Item=N82E16813130645

It is pretty cheap and you can get 6 gpus on there, which will give you an extra slot to expand.

As far as how to set it up (for 6 gpus, if you are only going to be doing 5 you should still be able to understand how) you will need 3 x1 to x16 powered adapter cables and 2 x16 to x16 riser cables.  Refer to this image (credit to ssateneth) https://dl.dropboxusercontent.com/u/9768004/z77ag45.jpg

If you only do 5 gpus, you wont need to pay attention to the presence short.  If you decide to go for it, look at these pics: http://blog.zorinaq.com/images/pcie-short-schematic.png and http://blog.zorinaq.com/images/pcie-short-photo.jpg

You simply plug the adapters and riser in the slots and then put your cards in.  Then you should be good to go.

[jaywaka2713]

I would recommend the MSI Z77a-G45: http://www.newegg.com/Product/Product.aspx?Item=N82E16813130645

It is pretty cheap and you can get 6 gpus on there, which will give you an extra slot to expand.

As far as how to set it up (for 6 gpus, if you are only going to be doing 5 you should still be able to understand how) you will need 3 x1 to x16 powered adapter cables and 2 x16 to x16 riser cables.  Refer to this image (credit to ssateneth) https://dl.dropboxusercontent.com/u/9768004/z77ag45.jpg

If you only do 5 gpus, you wont need to pay attention to the presence short.  If you decide to go for it, look at these pics: http://blog.zorinaq.com/images/pcie-short-schematic.png and http://blog.zorinaq.com/images/pcie-short-photo.jpg

You simply plug the adapters and riser in the slots and then put your cards in.  Then you should be good to go.

Some questions:

1. I think I finally understand how these >4 GPU systems work. I didn't know what a riser cable was, but basically it allows you to run a GPU off a x1 port? Correct me if I'm wrong. It needs to be powered though because the x1 port doesnt provide as much power as the x16. I'll also probably end up buying x16 to x16 powered risers.
2. What does it mean when you have a powered riser with Molex? What's Molex?
3. Is the 7950 better than the 7970? I've heard here that it is. Not completely sure though, and it doesnt make since due to it being lower in the series. Won't go 7990 because of the price gap. The 7970 does better than the 7950 in hashpower, but can I overclock 5 (or even 6) 7950s to 7970 speed?
4. Does the PCIe 3.0 increase hashpower at all over the PCIe 2.0 slots?

[Malawi]

I would recommend the MSI Z77a-G45: http://www.newegg.com/Product/Product.aspx?Item=N82E16813130645

It is pretty cheap and you can get 6 gpus on there, which will give you an extra slot to expand.

As far as how to set it up (for 6 gpus, if you are only going to be doing 5 you should still be able to understand how) you will need 3 x1 to x16 powered adapter cables and 2 x16 to x16 riser cables.  Refer to this image (credit to ssateneth) https://dl.dropboxusercontent.com/u/9768004/z77ag45.jpg

If you only do 5 gpus, you wont need to pay attention to the presence short.  If you decide to go for it, look at these pics: http://blog.zorinaq.com/images/pcie-short-schematic.png and http://blog.zorinaq.com/images/pcie-short-photo.jpg

You simply plug the adapters and riser in the slots and then put your cards in.  Then you should be good to go.

Some questions:

1. I think I finally understand how these >4 GPU systems work. I didn't know what a riser cable was, but basically it allows you to run a GPU off a x1 port? Correct me if I'm wrong. It needs to be powered though because the x1 port doesnt provide as much power as the x16. I'll also probably end up buying x16 to x16 powered risers.
2. What does it mean when you have a powered riser with Molex? What's Molex?
3. Is the 7950 better than the 7970? I've heard here that it is. Not completely sure though, and it doesnt make since due to it being lower in the series. Won't go 7990 because of the price gap. The 7970 does better than the 7950 in hashpower, but can I overclock 5 (or even 6) 7950s to 7970 speed?
4. Does the PCIe 3.0 increase hashpower at all over the PCIe 2.0 slots?

Seems like you should have done some more reading and searching first. I am a total noob on mining, yet I can answer some of your questions.

1. The power comes from some of the first wires. A x1 can get as much power as an x16 trough the MB. The extra wires is for extra bandwith(speed). This speed is needed for playing games where lots of data is sent to the card for calculation, and a lot of data is returned. With mining only a small amount of data is sent to the GPU, it then churns away and spit out a small amount of data.
The powering of the riser is to protect the MB as it's not made to put out that much power from the sockets.

2. It means that you supply the card directly with power that would otherwise go trough the MB, and possibly fry the MB. Molex is the standard (old school) power-connectors in your computer.

3. 7970's are faster, but 7950's are better compared to price and power usage.

4. No.

[middlemarkal]

I would recommend the MSI Z77a-G45: http://www.newegg.com/Product/Product.aspx?Item=N82E16813130645

It is pretty cheap and you can get 6 gpus on there, which will give you an extra slot to expand.

As far as how to set it up (for 6 gpus, if you are only going to be doing 5 you should still be able to understand how) you will need 3 x1 to x16 powered adapter cables and 2 x16 to x16 riser cables.  Refer to this image (credit to ssateneth) https://dl.dropboxusercontent.com/u/9768004/z77ag45.jpg

If you only do 5 gpus, you wont need to pay attention to the presence short.  If you decide to go for it, look at these pics: http://blog.zorinaq.com/images/pcie-short-schematic.png and http://blog.zorinaq.com/images/pcie-short-photo.jpg

You simply plug the adapters and riser in the slots and then put your cards in.  Then you should be good to go.

Some questions:

1. I think I finally understand how these >4 GPU systems work. I didn't know what a riser cable was, but basically it allows you to run a GPU off a x1 port? Correct me if I'm wrong. It needs to be powered though because the x1 port doesnt provide as much power as the x16. I'll also probably end up buying x16 to x16 powered risers. some of the power for the card comes from the pcie slot and 3 is the max the motherboard can give so you need an external source of power ie the molex plug
2. What does it mean when you have a powered riser with Molex? What's Molex? the molex plud is the 4 pins D shaped CD-ROM and PATA harddisk power plug
3. Is the 7950 better than the 7970? I've heard here that it is. Not completely sure though, and it doesnt make since due to it being lower in the series. Won't go 7990 because of the price gap. The 7970 does better than the 7950 in hashpower, but can I overclock 5 (or even 6) 7950s to 7970 speed? to mine 7950 is almost as good as 7970 and cheaper
4. Does the PCIe 3.0 increase hashpower at all over the PCIe 2.0 slots?no advantage

[jaywaka2713]

Last question. I've heard some discussion about running a rig with more than one PSU. Is there a way to chain, say two 850W PSUs together? Would that be better than using just one 1600W PSU?

[Malawi]

Last question. I've heard some discussion about running a rig with more than one PSU. Is there a way to chain, say two 850W PSUs together? Would that be better than using just one 1600W PSU?

Yes, it is possible. http://www.masswerk.at/googleBBS/

[jaywaka2713]

Last question. I've heard some discussion about running a rig with more than one PSU. Is there a way to chain, say two 850W PSUs together? Would that be better than using just one 1600W PSU?

Yes, it is possible. http://www.masswerk.at/googleBBS/

LOL so i searched (learned lesson from your trolling [use lmgtfy.com]) with that tool and actually found what I was looking for. Cool. Hopefully I can get this rig setup no problem.

[Malawi]

Last question. I've heard some discussion about running a rig with more than one PSU. Is there a way to chain, say two 850W PSUs together? Would that be better than using just one 1600W PSU?

Yes, it is possible. http://www.masswerk.at/googleBBS/

LOL so i searched (learned lesson from your trolling [use lmgtfy.com]) with that tool and actually found what I was looking for. Cool. Hopefully I can get this rig setup no problem.

Nice. 

And I know that it sometimes feels better to search and find something rather than just getting handed the answer. 

[jaywaka2713]

Last question. I've heard some discussion about running a rig with more than one PSU. Is there a way to chain, say two 850W PSUs together? Would that be better than using just one 1600W PSU?

Yes, it is possible. http://www.masswerk.at/googleBBS/

LOL so i searched (learned lesson from your trolling [use lmgtfy.com]) with that tool and actually found what I was looking for. Cool. Hopefully I can get this rig setup no problem.

Nice. 

And I know that it sometimes feels better to search and find something rather than just getting handed the answer. 

Very true. First time I saw lmgtfy.com it was funny but you have a good point. Your google frontend is even better though lol.

[iletras]

I'm looking to do a 5 card rig and I'm a little stuck also.

I've ordered 5 770x cards but,

1) I don't know what motherboard to get (gotta admit I'm a little confused by what to do where and how on the MSI 277A-G45 - skipped too many EE classes maybe, may be just plain stupid, not smart enough to know which...)
2) how big a power supply I'll need (1000W maybe? 1050W? even bigger?).

Thanks ya'll! 

[johnsl]

This thread was from last May.

Hardware that was viable then is now completely redundant and will never get near mining a single bit coin.

If you don't understand how the increase in difficulty in the bitcoin process makes this happen then you really need to go back and read a lot more before you even think about buying mining hardware.

John S-L

[Lamber]

search the forums for MB supporting 5 cards.

[justbtcme]

There is a MB that supports 12 GPU

[Lamber]

There is a MB that supports 12 GPU

What is that MB, link?

[Stinky_Pete]

There is a MB that supports 12 GPU

What is that MB, link?

You could probably put together a machine with 6 dual-GPU cards on an ATX motherboard. But it would need custom-built drivers. Windows or mainstream Linux will not support that many.