Topic: Cheap and Easy to Get Motherboard for 2 GPU (Read 4474 times)

+1

I've got one of these as my test board. It's currently churning out 400 MH/sec. I use it to flash BIOSes of 6950s.

For the OP - this particular board (mine is the E35M1-M without the 'Pro' - the Pro simply runs the CPU faster and has a fan on the CPU heatsink, whereas the non-Pro doesn't have a CPU fan, just a heatsink) has the CPU / GPU soldered to the logic board. It's all integrated, and the non-Pro version (mine) only has a passive heatsink on the main chip (AMD call it the 'Hudson' core, and also anything including CPU, ALU, GPU - it does all of the functions).

I think I paid around £80 for the board. This is a microATX logic board, AMD Hudson CPU / GPU included, fanless heatsink, and memory. Basically, an entire PC ready to go, just add hard drive and power supply.

It has two PCIe slots. One full length x16, one x1. To use the x1, you need a PCIe extender. Both work using extenders.

I've stuck an old CPU fan on top of the heatsink for safety, but it rarely uses much CPU anyway. It's a very cost effective 'test' rig for Bitcoin mining.

However, if you plan to quit mining at some point, and then use the machine (with its monster GPUs) as a gaming box, you'll find that this particular option will be horribly underpowered in the CPU department. It's only of use as a casual machine, or for an application that only requires GPU power.

Mine has also been VERY reliable. Linux *does* make some snarky remarks about the Hudson CPU in the kern.log so I assume it's tricky in some way and needs driver tweaks. However, this board is the ONLY machine I own that has a native Windows installation - I'm using XP because the GPU BIOS editing and flashing apps are only available on Windows or DOS. Windows works well enough (as far as I can tell) on the board, and since I use Linux for mining, I can vouch for the board working well with both operating systems. It won't run OS X though, AFAICT.

Biostar A870U3, they were $45.99 shipped at newegg a while back.

You shouldn't have much problem finding a board in the $50-60 range for 2 slots. Even some 4 slot boards can be had that low. I've got a $99 Gigabyte GA970A-D3 which has 2 x16 and 3 x1 slots. You shouldn't need to spend that much for only 2 slots.

If I were still looking I think I'd use NewEgg to narrow down suitable boards according to features/price and then plunk the model # into the forum search and see if you get any users reporting results/problems with the board.

I have a brand new AMD AM3+ ASUS mobo I could sell you : http://www.newegg.com/Product/Product.aspx?Item=N82E16813131728


Expansion Slots

PCI Express 2.0 x16
    1

PCI Express x1
    2

PCI Slots
    1



-ST

If you only want 2 GPUs, you could use the Asus E35M1-M Pro http://www.newegg.com/Product/Product.aspx?Item=N82E16813131697

Nice and small board, low power consumption. You will need at least one PCI-e riser.

Sure, this makes sense. The only thing to be aware of is that some motherboards are more finicky than others about running GPUs in the x1 slots. Some boards require that you short pins in order for this to work. The two threads below might be helpful for getting a sense for which brands will be easier to work with.

https://bitcointalksearch.org/topic/motherboards-what-works-wfour-or-more-gpus-list-them-37880

https://bitcointalksearch.org/topic/list-of-motherboard-that-require-shorting-pin-a1-b17-for-pci-e-1x-to-work-36061

Not actually, I am thinking of using the 1 PCIe 16x slot and another GPU connected to the 1 PCIe1x slot which should be more easily available.  That's why I am looking for such motherboards.  Does it make sense or am I missing anything?

If you are not planning to invest in 2 GPUs right away then I would advise you to go for a motherboard with only 1 PCIe 16x slot. Since, I know in certain local stores the price difference between a motherboard that has support for 1 slot as opposed to a M/B with support for 2 slots is way too much.

Instead you can save on that much money and invest it in a more powerful PSU which you can use later even with 2 GPUs.

The price difference between an ASUS M/B with 2 PCIe 16x slots and the one with only 1 PCIe 16x slot is 2 times. It just depends on where you are located and what boards are available.

Any board with two pcie slots for the GPUs will do. Try to find one where the slots are spaced apart pretty well to give your cards room to breath. You probably want a board that is compatible with cheap AMD CPUs (i.e Sempron or Athlon). And think about future expansion. Some boards have an additional two pcie x1 slots, so you can get 4 GPUs working on one board with risers. Personally I like the Biostar A870U3 (around $65 USD). The only "con" with this board is that if you don't use risers, the two GPUs are quite close together. But my guess is that most cheap boards will be this way.

I am trying to get some cheap and easy to find MB for 2 GPUs, wonder if there is any recommendations?