What motherboard for a GPU setup?

[3LP]

Hi there,

I'm in the process of creating a node for GPU rendering. (Or maybe few depending of the next service pack )
I would like to put in as many GPU as possible. It would really only by used to spawn RT GPU on it.
I remembered of this thread with 8 GPU,:
http://www.chaosgroup.com/forums/vbu...8-GPU-System-)

This was a long time ago, so I was wondering if there was any other solution since?
I would say that cheap is better, knowing that it's always better to have more cheaper than few more expensive.
It would only be a container for the GPU, so the PCI-E lanes are the more important, the cpu and ram would be as low/cheap as possible.

I guess that for the gpu part, the best way would be to go for those GTX680 4Go, unfortunately the GTX580 are not available easily any more, and they have only 3Go of ram. Do the GTX670 have a better performance/price ratio?

Otherwise, I was thinking of using the old EVGA X58 Classified 4-Way SLI, but the cpu for that one are still nearly $1k, which is way to expensive for "only" running windows...

Any other ideas? Like those cubix Xpander (but I've heard they are crap and really not reliable)?
Plus, having the computer as a node so that any production member could use it is a big advantage...

Thanks

Stan

[Dariusz Makowski (Dadal)]

Im not sure but I think u need quite strong CPU with 5-7 GPUs to support GPU with render data.

In any case get one of EVGA 7 PCI-e boards(SR-2, SR-x) 1 xeon(u should not need 2 on this mobo) and then 7x gtx 680 4gb all water colled since they wont fit with stock fans.

[3LP]

Nice one, I just saw that the cheap xeon for that motherboard would be only $200. Good news compared to $1k for the desktop version.

I was thinking of buidling something like that :




So I would not be constrained with space and heat...

Vlado, do we effectively need a lot of cpu power to sustain the gpu render?

Thanks

Stan

[vlado]

Vlado, do we effectively need a lot of cpu power to sustain the gpu render?

That's a good question; let me do some benchmarks with our setup and I'll let you know.

Best regards,
Vlado

[3LP]

Thanks Vlado!

Another dodgy solution would be to do this :

https://bitcointalk.org/index.php?PH...opic=7216.1680



Stan

[Dariusz Makowski (Dadal)]

Manu universities does stuff like that now days. Jank a shell/home made rack and spam them with GPU units hehe

[vlado]

Manu universities does stuff like that now days. Jank a shell/home made rack and spam them with GPU units hehe

Yeah and you'll never guess what they use them for Not for scientific computing for sure...

Best regards,
Vlado

[urbanite]

At some point it was popular to use them for producing bitcoins

[3LP]

Hey there,

Well, what to say, with the new release of SP4, we are definitly going to buy some GPU nodes now.

So my question remains the same, what motherboard should we go for?
The SR-2 or the SR-X?
The problem with those are that they both have 7 PCI-E 16x but not all of them are 16x.

From EVGA's Manual :



Vlado, does that change much? Are the PCI-E lanes used at more than 50% when rendering? Should we go only for 4 GPU on those type of cards?
If yes, are there other motherboards that have 7-8 PCI-E 16x? But real 16x?

Or do we really need to go for the TYAN motherboards?
http://www.tyan.com/product_SKU_spec...&SKU=600000150

As a side note, any chance you would have any new with those benchmark Vlado?

Thanks

Stan

[Dariusz Makowski (Dadal)]

Interesting. Its also worth noticing that motherboards has a GPU limit on them. EVGA can only handle 7 GPUs or so. So if you want 8x graphic card with 2x GPU each you have to make sure ur motherboard can handle 16 GPU cores. Maybe a micro motherboard is better choice as its more in to server motherboard business...

Thanks, bye.

[vlado]

As a side note, any chance you would have any new with those benchmark Vlado?

Yes, the machine that we used for the Forest Pro demo has 4 GPU cards; the CPU usage for the i7 managing them was about 20%

Best regards,
Vlado

[3LP]

Ah haaa, nice one Vlado,

interesting!

I know this could be a weird/silly question, but :
Is RT multi-threaded in terms of handling the GPU? I guess so, but I just want to make sure.

I'm asking this because I'm thinking of putting a Intel E5606 on a SR-2 and that cpu is only clocked at 2.13 GHz, so if RT doesn't handle multi-threading CPU for handling the gpus, it's better to go for a cpu with a high core speed, isn't it?

I might repeat my self, but, do you know as well if it's a problem or if we have some performance issues if we put GPUs on PCI-E 8x?

Thanks

Stan

[vlado]

Is RT multi-threaded in terms of handling the GPU? I guess so, but I just want to make sure.

Yes, it is. It's better to have several cores, the actual GHz probably don't matter that much.

I might repeat my self, but, do you know as well if it's a problem or if we have some performance issues if we put GPUs on PCI-E 8x?

I don't know to be honest; if you can make tests, it would be best.

Best regards,
Vlado

[3LP]

All good Vlado

Just out of interest, what was your demo setup? Motherboard and CPU?
(It might be just more simple to stick with 4GPUs per board and new hardware.)

Thanks

Stan

[Dariusz Makowski (Dadal)]

Ums regarding SR-2 I have it and just a world of advice. GET A BIG CASE. That motherboard is huge, I'm using Xigmatec Elysium.