Could someone recommend me a motherboard for 4 cards?

[DupingBitCoins]

Trying to find a decent one but not so pricey and with 4 slots for the cards.

[V2-V3]

Here ya go http://www.newegg.com/Product/Product.aspx?Item=N82E16813131714R

Im not sure what your budget is but this might be your best option as any less expensive 4 slot board with the right spacing is out of stock.

[smell]

Trying to find a decent one but not so pricey and with 4 slots for the cards.

There are also some 790FX and 890FX boards that come with 4 PCIE slots.  Here's a cheap one:

http://ncix.com/products/?sku=58759&vpn=890FXA-GD65&manufacture=MSI%2FMicroStar

I have MSI's 790FX board.  Something you may want to consider is cooling: I've found that having more than two in a box gets hot quickly.  I needed a household fan blowing on em constantly or they would crash.  So I've settled on two to a box now.

EDIT: whoops, that one has 4 PCIE-1 slots... here's the one I was thinking of...

http://ncix.com/products/?sku=52498&vpn=890FXA-GD70&manufacture=MSI%2FMicroStar

[phenom]

This one has 6 PCI-E slots 

http://www.newegg.com/Product/Product.aspx?Item=N82E16813130274&Tpk=MSI%20890FXA-GD70%20890FX

[LeonGeeste]

Wow, didn't know so many people were going for this now.  I've managed to set one up here's what it looks like, parts list in the comments.  But be warned: you NEED liquid cooling if you want to cram that many that close together!

[smell]

Wow, didn't know so many people were going for this now.  I've managed to set one up here's what it looks like, parts list in the comments.  But be warned: you NEED liquid cooling if you want to cram that many that close together!

Nice rig.  How much was the liquid cooling system, that is, if you don't mind revealing that info?

[phenom]

Wow, didn't know so many people were going for this now.  I've managed to set one up here's what it looks like, parts list in the comments.  But be warned: you NEED liquid cooling if you want to cram that many that close together!

Nice setup. What OS are you running those on? If you're getting 1.3 GH/s from 4 cards, I take it your not overclocking?

[LeonGeeste]

@smell and phenom: Thanks guys!

Here's the cost breakdown for the system:

4x XFX Radeon HD 5870 GPU, $250 each -> $1000
4x VID-AR587T2 GPU waterblock $100 each -> $400
1x Coolermaster HAF X Chassis -> $200
1x Antec HCP-1200 ATX PSU -> $285
1x MSI 890FXA-GD70 Motherboard $200
1x Swiftech H20-320 EDGE liquid cooling kit (comes with tubing, 4 barbs, and clamps) -> $265
1x 1/2 inch elbow barb to make that connection at the bottom work $13
3x connectors between waterblocks, $12 each -> $36

1X Kingston ValueRAM 2 GB 1333MHz PC3-1066 DDR3 DIMM $23
1x AMD Sempron 140 Socket AM3, 2.7 GHz, 1 MB Cache, 45 Watts, $38

Total: $2,460

I've bolded the watercooling-specific items, which together sum to $714 (not including shipping).

I'm using Ubuntu 10.10, and I've since started overclocking, so I get 1.65 GH/s.  But I'm only overclocking it to the top of the OEM-specified band, I don't know how to make it go higher, as some of the other miners in the comparison chart seem to.

[smell]

I've bolded the watercooling-specific items, which together sum to $714 (not including shipping).

OUCH 

Is it quiet?  I hope it's quiet.

[AndyRossy]

Did you actually run it on air for any period? How long until it overheated? Was it with stock coolers?

[mouser98]

here is the one that i got with 4 pci-e slots for $65

http://www.newegg.com/Product/Product.aspx?Item=N82E16813138318

[computerparts]

here is the one that i got with 4 pci-e slots for $65

http://www.newegg.com/Product/Product.aspx?Item=N82E16813138318

That board only has two pci-e slots which can be used with video cards.

[DupingBitCoins]

here is the one that i got with 4 pci-e slots for $65

http://www.newegg.com/Product/Product.aspx?Item=N82E16813138318

That board only has two pci-e slots which can be used with video cards.

Yeah I was like hell yeah 64 bucks then got confused for a second.

[mouser98]

here is the one that i got with 4 pci-e slots for $65

http://www.newegg.com/Product/Product.aspx?Item=N82E16813138318

That board only has two pci-e slots which can be used with video cards.

lol, tell that to my four 5830s then

[Skunkworks]

This one has 6 PCI-E slots 

http://www.newegg.com/Product/Product.aspx?Item=N82E16813130274&Tpk=MSI%20890FXA-GD70%20890FX

Question: can either windows or linux support this many GPUs, and does the BIOS?

If the answer is yes, I can 6x 5770 being very practical in this setup.

[LeonGeeste]

I've bolded the watercooling-specific items, which together sum to $714 (not including shipping).

OUCH 

Is it quiet?  I hope it's quiet.

Yep, it's quiet.

[LeonGeeste]

Did you actually run it on air for any period? How long until it overheated? Was it with stock coolers?

I tried running the four of them on air.  Bad idea.  Once you start hashing, the hottest one, within about 15 seconds, exceeds 90 C and just keeps getting hotter.  So for a while I just ran two, and they'd still get hot, with the hotter one at about 85 C.  And that's of course without overclocking.;  Once I set up the liquid cooling with overclock, I could do four and keep them at about 65 C.

And yes, it's expensive, but the system has more than paid for itself, even ignoring the resale value of the system.

[AndyRossy]

Great much thanks for the reply & advice!

Im currently setting up a 3 x 6950 rig - waiting on PCIx1 risers.  Im hoping that, assuming I set them nicely spaced in the case, air cooling should still just about work.  If not, $700 hit incoming .

[jonnynogood]

Trying to find a decent one but not so pricey and with 4 slots for the cards.

i just set this up today with 4 6870 cards

http://www.newegg.com/Product/Product.aspx?Item=N82E16813157198
90 bucks

320 bucks for everything but the cards (850w gold power supply)

you need 2 riser cables and some kind of case but its cheap

[DupingBitCoins]

Trying to find a decent one but not so pricey and with 4 slots for the cards.

i just set this up today with 4 6870 cards

http://www.newegg.com/Product/Product.aspx?Item=N82E16813157198
90 bucks

320 bucks for everything but the cards (850w gold power supply)

you need 2 riser cables and some kind of case but its cheap

What are riser cables exactly? I've never used them, got a link where I can buy? Why do I need them in the first place, and is it just for that CPU? I also only see two slots.. o.O