Gigabyte X58 UD 9 - 8 GPU system

[Dionisio]

Hi all, I decided to write my very last and new experience here.

We produce high quality rendered images and we build a new crazy configuration to use with the new iray GPU renderer.
iray uses nVidia's CUDA and more GPU you can use faster the results!

So, we decided to build an 8 GPU solution based on this particular hardware:

GIGABYTE X58 UD9
Intel i7 970
24GB ram
8 nVidia 480GTX cards
4 CUBIX boxes

The 4 CUBIX hardware are connected on 4 PCI 16x slots via 4 8x adapters.
The PCI bandwidth is only important during the loading data operation of the scene in the card's memories.
After that we noticed that the PCI bus is not saturated.

The cards are installed and recognized by the system perfectly. The problem we have is that we can work at high speed with 7 cards.
Every time we try to add the 8th card the GPUs load gets really bad! We're trying to understand what's going on.

So my question is: The UD9 has any limit? It supports officially only 7 GPU cards? Do we have a certain BIOS limit?
We don't use SLI in this configuration as CUDA doesn't use it obviously.

Thanks in advance,

Dionisio -

[Dark Mantis]

Hi and welcome to the Gigabyte Forum.

That system certainly has some number crunching capabilities! I reckon it would work well as a Folding@Home workstation when not in use.
I'm really not sure what sort of limitation you have come up against here, possibly being limited by the processor? I'm afraid i don't know enough about the hardware involved to make an informed decision.