8 GPU limitation

[p3taoctane]

Moved this to General

I see somewhere in this thread someone saying you can't run more than 8 GPU's in one system.

My experience backs that up as I tried to get 9 going once with 8 rendering and one display. (Using an extension box) and it only saw 8 cards.

It is a little off topic... but WHY IS THIS. Is it a windows limitation, a mother board limitation?

There are Trenton Expansion chassis with 17 PCIe x 16 Gen 2.0 slots so you could fit 8 doubles at least with a 2430 watt PSU incorporated in it. Then as many as 7 more in your connect CPU

I'm guessing if this could have been done... someone would have done it. I tried working with a company to do some tests on cloud rendering... but they were only letting me log into 4 card systems. If OTOy wants to do cloud based rendering I am assuming they will be doing more that 8 cards.

I do not plan on going out and purchasing 16 Titan cards anytime soon... but I bet 580s aree going to come down eventually and a 16 card system would not be out of the question.

Kind of a dreamer topic... but has anyone here looked into why it is only 8?

Peter

[Carl S.]

As far as I know it is a Windows limitation.

[glimpse]

but I bet 580s aree going to come down eventually and a 16 card system would not be out of the question.

they will probably not come down, but be GONE down. by that I mean, 'cause they are out of production, soon might be hard time to find them out..even this day You could not buy new one just antwhere. so You'll be forced to look for second hand products, but who knows how they've been treated? and again..how much all this rig draws of electricity and how much heat it would output..I'd better switch for something new..pluss vRam, pluss textures..Price is not the only factor.

[p3taoctane]

Thanks
Does anyone know if Linux has the same limitation?

Peter

[abstrax]

When we built our render machine with 4 690s, we ran into driver issues. I got in touch with NVIDIA and the reply was inconclusive. They said that they never test the drivers with that many GPUs and it could also be a limitation of the motherboard. Interestingly, 2 days later version 310.90 was released and all problems were gone. It may have been a coincidence, but maybe not.

Anyway, the render machine runs those 4 690s plus an Intel GPU (HD4000) for display and it seems to work fine. So in general there doesn't seem to be a limitation of 8 GPUs only.

Cheers,
Marcus

[p3taoctane]

Thanks Abstraxt
I wonder if in the 690's work cause they are 4 slots (8 gpus) as opposed to 8 actual slots

[abstrax]

Thanks Abstraxt
I wonder if in the 690's work cause they are 4 slots (8 gpus) as opposed to 8 actual slots

Could be. I really don't know. I'm more into software than hardware...

[p3taoctane]

For that I am eternally gratefull

It is not like I can build a 16 card system... it is just that no one really seems to know... and I am interested to find out what is stopping a 16 card beast be built

[AarDeJ]

How is this so? I thought 5 gup's were the limit with open cl. If more than 5 gpu's software display mode is needed?

[BorisGoreta]

Have you tried Windows 8.1 ? I got rid of some problems when I switched to it. My OpenGL didn't work correctly if I had more then 4 cards in Windows 7. In Windows 8.1 I am not having this problem.