OTOY Forums

It has 2x 128 cores and 2x 512mb
If you disabled SLI - run in parallel together - I would think it will run about 1/2 speed of a GTX480 ie it would be have adequate performance = 256 cores with 512mb vram for Octane purposes.
The vram would be limiting though.
It would be ok for simple scenes, maybe 1 million poly + a few textures @ say 2400*1800px.
It depends what you needs are. I think most people would have difficulty with 512mb.
If you have this card already it would be ok to use it but I dont think it is a good choice to buy especially for Octane. They were $600 when they came out.
A GTX460 would be better with either 1gb or 2gb vram. It would be faster and only ~$200

It you have 2 x 9800gx2 it would be 512 cores but only 512mb vram still.
The reason is that the same Octane data is loaded into memory for each GPU and they run in parallel - ie each contibutes to working on the same scene. Octane doesnt use SLI.
Effectively you have 4xGPU with 512mb.
The vram is not added together.

You could buy 460/1gb for the same money I think. This would be 672 cores.
It would be prudent to buy a more recent card that is made with higher Cuda capability and hence future compatibility with Octane developments and Nvidia driver updates.
The 9800gx2 really is related to the 8800 which is a v good card but superceded by Fermi generation.
Together they will also consume less power 320W vs 400W and take up less space.
It would not be my recommendation to go with a card with 512mb, in fact if I had to I would say go for the 2gb one but your needs might be modest. Definitely I would suggest 1gb over 512mb if you are buying new.

Hey ettore,

I had MSI 9800 gx2, it's not a bad card but you'll need a minimum 750w power supply for ONE card. The system just won't boot with the less.... so gtx 460 (or better) is the way to go.

hi guyz am not so clear about how multiple graphics card work in octane, if ur vram in multiple gpu doesn't scale up then how does octane benefits from multiple gpu,

which is more important cuda cores or vram ? everyone seem to stress on vram ?

anomi wrote:hi guyz am not so clear about how multiple graphics card work in octane, if ur vram in multiple gpu doesn't scale up then how does octane benefits from multiple gpu,

which is more important cuda cores or vram ? everyone seem to stress on vram ?

the more cards the more speed, and the more memory the more complex scenes you can render.
the scene needs to be copied into each card though, so having 4 cards with 2GB each gives you 2GB of scene data, which allows you to render some decent sized scenes.

Radiance

thanks radiance i get the point,

sorry for being such a bug with my questions
so if 2 gpus run at x8 instead of at x16 in pci e slots would that diminish the performance of both cards in general and in octane?


i plan to buy 2 gtx 480 but my only challenge now is getting an expansion case like cubix (too bad u guyz aint producing anymore)

well iv been scouting around for some so far iv seen pci e with inconsistent slot speed ie x16 and x8, even x4 in the same casing

don't now if that would hinder performance when they both run at x8 as opposed to x16. any major difference? thanks

You can still but a Xpander box from Cubix, they are still producing them. Refractive never was. Personally I would recommended one.

I would recommend getting one card to start and waiting for our new expansion solution.

Radiance