OTOY Forums

Hey,
I'm looking to build a workstation using a server mainboard (probably 2x8 core AMD System) but so far I have yet to see a mainboard that supports multiple double-slot graphics-cards.
Is there some solution (riser-card maybe) for this?
Also, do you expect the GTX 460 or the 465 to be faster with Octane?

We haven't had any multiple performance reports on the new GTX460 so i can't say.
although the GTX465 can be unlocked to a GTX470 so i imagine it would be a better buy,
if noise and heat aren't too problematic, and you want a bit more GPU memory to render large format or larger scenes.

Radiance

I have looked into the unlocking of the GT465 and it seems that only a smaller number of them can be successfully unlocked and don't I see the possibility to buy one with a guarantee that it is unlockable. Regarding the game performance the consensus seems that the 460 will perform better in almost all cases, but I am not so sure about the GPGPU performance.

maybe try to look into the new 2GB GTX460's.
memory is very important for octane.
you can even add a 2nd one to get faster speed than a GTX480.

Radiance

Sorry, newbie here but one question I need to ask is how do you connect 2 graphics cards in one motherboard without putting it in Sli mode? How would octance utilize the other one, if lets say the primary video card is connected to the monitor? What happens to the second one?

Sorry to ask these question but not too techie when it comes to hardware stuff.

Thanks in advance.

just buy a motherboard with 2 PCI-E x16 full length slots,
and plug in the 2 cards, go to your nvidia control panel after installing the latest drivers (this is all for windows), and turn off SLI. (it might be off by default)

some multi slot motherboards don't support SLI, but still can be used to run octane on multiple GPUs as octane does'nt use SLI at all. (in fact it can't use multi gpu setups when SLI is enabled)

when using SLI, one normally connects a bridge flatcable/connector between one, two, three or 4 cards.
this is not necessary for octane, and you can run octane in multigpu mode with this bridge attached provided you switch SLI off in the nvidia control panel.

Radiance

2gb gtx460 sli (tot 4gb) = 4gb to use for one scene ? is that right?

thedreamers wrote:2gb gtx460 sli (tot 4gb) = 4gb to use for one scene ? is that right?

no, only 2GB. octane needs a copy of the scene in both GPUs, as they both need to trace rays into the whole scene and find any geometry.

Radiance

Hi, I´m new to the GPU movement, but would like to try it out before building a new workstation.
Is it possible to mix two different GPU´s (f.i a GT240 and a GTX460). They both have 1 Gb internal, but does it matter that one is much slower in CUDA? Otherwise I need a new motherboard for two dual slot cards, hence a new processor and a new cooler etc. That´s okay if it works, but I would like to try it out with the above combi in my existing setup.

Will Octane use both GPU´s to the maximum in such a config?

Yeah, octane can use any pair or more of Nvidia Cuda capable GPUs.
Although you won't get linear speedup with GTX200 series or lower,
and you will get the best performance when rendering larger resolution, path traced images for finals.

for editing your scene i'd recommend to use the fastest card as the octane card, and don't connect it to the display,
use the slower card for display, that way you have a smooth UI in your OS while octane is running in the background.

Radiance