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Other => CPU/GPU Bitcoin mining hardware => Topic started by: RandyFolds on July 31, 2011, 10:15:19 AM



Title: 5 GPUs...can I do it?
Post by: RandyFolds on July 31, 2011, 10:15:19 AM
I stumbled across an extremely inexpensive cache of 5830s from a friend. I am currently running 2x6870s in a Silverstone Raven 2. I was thinking about getting PCIe extender cables and unscrewing the stupid acrylic viewing window (or maybe cutting it so as not to affect flow-through) and running three 5830s outside the case, with either a throttled 100 watt can fan venting heat out the window or just a box fan blowing at it if it doesn't make the house unbearable. I would have to rig up some sort of mounting hardware for them, but I'll cross that bridge if this is even possible. I was thinking of running a tandem power supply to ensure that everything had enough juice. I happen to have an Antec 500w that vents such that I could mount it in the case with my other PSU, an Antec 750w.

My alternative would be to assemble some bones I have lying around, but I would need a processor and HD, and then I'd need a more robust PSU than that antec 500w, so I am looking at $200 + cards, and probably higher power costs due to the secondary systems. I would prefer to cram it in one box, even though it is getting to be the height of summer. Fall and winter can do with a spaceheater; all the better if it generates btc.

Yea or Neigh? Thanks for your input.


Title: Re: 5 GPUs...can I do it?
Post by: Elder III on July 31, 2011, 01:38:46 PM
you can do it if your motherboard supports it...  ;)


Title: Re: 5 GPUs...can I do it?
Post by: deslok on July 31, 2011, 03:46:10 PM
Send them to one of us we're crazier than you! Kidding though you can do it


Title: Re: 5 GPUs...can I do it?
Post by: RandyFolds on July 31, 2011, 07:04:33 PM
Make sure your logic board can support PCIe cards in ALL slots. Some share bandwidth in such a way as to effectively disable certain x1 slots when the x16 slots are filled.

I've learned this the very hard way by spending quite a lot of money on what I thought was a good board with 5 slots - 5 extender cables and GPUs, only three of the GPUs are being recognised. I'd check first - certainly before butchering your case (if it's a nice case)...

And remember that GPU cards always seem to run cooler *outside* of a case than inside. Even without box fans etc. my open-frame rig is cooler than the case boxes.

Thanks for the help everyone.

The mobo is an MSI 870U-G55. Any clue how I can research whether it supports 5 PCI slots or not?


Title: Re: 5 GPUs...can I do it?
Post by: Inju on July 31, 2011, 07:10:14 PM
Make sure your logic board can support PCIe cards in ALL slots. Some share bandwidth in such a way as to effectively disable certain x1 slots when the x16 slots are filled.

I've learned this the very hard way by spending quite a lot of money on what I thought was a good board with 5 slots - 5 extender cables and GPUs, only three of the GPUs are being recognised. I'd check first - certainly before butchering your case (if it's a nice case)...

And remember that GPU cards always seem to run cooler *outside* of a case than inside. Even without box fans etc. my open-frame rig is cooler than the case boxes.

Can you share which mother board you used?
Coz, i am going to buy gigabyte 890FXA-UD7  AMD mother board with 6 PCIe slots to connect 6 cards with riser cables.


Title: Re: 5 GPUs...can I do it?
Post by: dishwara on July 31, 2011, 07:15:31 PM
Make sure your logic board can support PCIe cards in ALL slots. Some share bandwidth in such a way as to effectively disable certain x1 slots when the x16 slots are filled.

I've learned this the very hard way by spending quite a lot of money on what I thought was a good board with 5 slots - 5 extender cables and GPUs, only three of the GPUs are being recognised. I'd check first - certainly before butchering your case (if it's a nice case)...

And remember that GPU cards always seem to run cooler *outside* of a case than inside. Even without box fans etc. my open-frame rig is cooler than the case boxes.

Thanks for the help everyone.

The mobo is an MSI 870U-G55. Any clue how I can research whether it supports 5 PCI slots or not?
http://www.msi.com/product/mb/870U-G55.html#?div=Detail

says,
Slots
• 1 PCI Express x16 slot (PCI_E2) with x16 operation (PCI Express Bus SPEC V2.0 compliant)
• 1 PCI Express x16 slot (PCI_E3) with x4 operation (PCI Express Bus SPEC V2.0 compliant)
• 1 PCI Express x1 slot

meaning only THREE PCIe slots. NOT 5.


Title: Re: 5 GPUs...can I do it?
Post by: RandyFolds on July 31, 2011, 07:26:39 PM
Make sure your logic board can support PCIe cards in ALL slots. Some share bandwidth in such a way as to effectively disable certain x1 slots when the x16 slots are filled.

I've learned this the very hard way by spending quite a lot of money on what I thought was a good board with 5 slots - 5 extender cables and GPUs, only three of the GPUs are being recognised. I'd check first - certainly before butchering your case (if it's a nice case)...

And remember that GPU cards always seem to run cooler *outside* of a case than inside. Even without box fans etc. my open-frame rig is cooler than the case boxes.

Thanks for the help everyone.

The mobo is an MSI 870U-G55. Any clue how I can research whether it supports 5 PCI slots or not?
http://www.msi.com/product/mb/870U-G55.html#?div=Detail

says,
Slots
• 1 PCI Express x16 slot (PCI_E2) with x16 operation (PCI Express Bus SPEC V2.0 compliant)
• 1 PCI Express x16 slot (PCI_E3) with x4 operation (PCI Express Bus SPEC V2.0 compliant)
• 1 PCI Express x1 slot

meaning only THREE PCIe slots. NOT 5.


Yeah, I just noticed that as well. I have another mobo sitting around somewhere. I gotta see how many slots she holds.


Title: Re: 5 GPUs...can I do it?
Post by: RandyFolds on July 31, 2011, 07:27:22 PM
So much for last night's drunken plans... ;D


Title: Re: 5 GPUs...can I do it?
Post by: release on July 31, 2011, 08:08:50 PM
for future reference, GPUreview.com has the wattage of Reference cards.