motherboard for a mining rig

[goatpig]

I've seen dedicated mining machines with 4 video cards installed, but I can't seem to find cheap mobo with more than 2 PCI-E slots. Do you have to purchase a high end motherboard to run over 2 cards on the same pc or am i missing something?

[FRanz33]

I've seen dedicated mining machines with 4 video cards installed, but I can't seem to find cheap mobo with more than 2 PCI-E slots. Do you have to purchase a high end motherboard to run over 2 cards on the same pc or am i missing something?

pretty much.

[Cryptoman]

High end mobo, high end case, high end PSU, custom cooling.  You're better off sticking with two cards per machine and going with low-cost components.  Try not to skimp on PSU quality though.  A 650+ watt PSU from a trusted name like Corsair or Antec should do the trick.

[[Tycho]]

I've seen dedicated mining machines with 4 video cards installed, but I can't seem to find cheap mobo with more than 2 PCI-E slots. Do you have to purchase a high end motherboard to run over 2 cards on the same pc or am i missing something?

Actually you can't install more than 3 cards in ATX case because it allows only 7 expansion slots and each card needs 2.
Moreover, you can't place them next to each other because one card will block the air intake or anoter.

You are looking not for "PCIe" slots, but for x16 PCIe slots, that's not needed for mining. People with 4 cards in one MB usually connect them with flexible x1 PCIe extenders. Some of them even work. That's better for cooling too.

Also you can't power 4 good cards with one normal PSU. You'll need an expensive one or two good ones.

And Windows doesn't supports more than 4 GPUs. 4x5970 is like 8 GPUs, too much :)

[nster]

I've seen dedicated mining machines with 4 video cards installed, but I can't seem to find cheap mobo with more than 2 PCI-E slots. Do you have to purchase a high end motherboard to run over 2 cards on the same pc or am i missing something?

Actually you can't install more than 3 cards in ATX case because it allows only 7 expansion slots and each card needs 2.
Moreover, you can't place them next to each other because one card will block the air intake or anoter.

You are looking not for "PCIe" slots, but for x16 PCIe slots, that's not needed for mining. People with 4 cards in one MB usually connect them with flexible x1 PCIe extenders. Some of them even work. That's better for cooling too.

Also you can't power 4 good cards with one normal PSU. You'll need an expensive one or two good ones.

And Windows doesn't supports more than 4 GPUs. 4x5970 is like 8 GPUs, too much

Are you not sure? 

[rezin777]

I've seen dedicated mining machines with 4 video cards installed, but I can't seem to find cheap mobo with more than 2 PCI-E slots. Do you have to purchase a high end motherboard to run over 2 cards on the same pc or am i missing something?

Actually you can't install more than 3 cards in ATX case because it allows only 7 expansion slots and each card needs 2.
Moreover, you can't place them next to each other because one card will block the air intake or anoter.

I don't think he was concerned about fitting them in an ATX case, just the price of actually putting 4 on 1 board.

I currently have a 5870 smashed against a reference 5850 and it's working well enough. Temps on the 5850 stay around 62 at full load with a slight overclock (830). When I up the core voltage to stock 5870 specs, the temp approaches 70, but doesn't break it. That's running the card at 930 core though. Anyway, my point is that it's possible to put them right next to each other if you have positive case pressure and a nice exhaust fan directly above the cards. Or some other creative cooling approach. Then again I'm only doing it with 2 cards... so far. Oh and 60% fan speed on the cards might be loud for some!

[goatpig]

connect them with flexible x1 PCIe extenders.

That's what i was missing. thx.

[aistto]

Actually you can't install more than 3 cards in ATX case because it allows only 7 expansion slots and each card needs 2.
Moreover, you can't place them next to each other because one card will block the air intake or anoter.

You can use 14 expansion with http://www.negorack.ru/4u/NR--N406.html.