A question about cards

[gordonrobb]

I have a new machine with one GTX 680 2GB and I'm loving what Octane can do with it. I would however like to give it some more power, so am looking at getting an additional card. I have some questions about this.

Firstly, I would like to have a card that I can use for the GUI, while haveing the other card set for Octane's use. I only really need to do this during set up, and would give Octane both cards during final render. I know I can do this with the LW plugiin, but can standalone do it too?

Secondly, if I get a second card that is different (looking at a 670 4GB) I'm ok with the fact that if octane is using this card things will be fine, but if I give it both the 2GB 680 and the 4GB 670, will they still play nice ie will my performance be scaled, and also does this mean my total memory available to meshes and textures will be 6GB?

Thanks for your help anyone.

btw, the reason I'm not just getting another 680 GB is I'm trying to get the biggest bang for my buck and I don't have that much buck. Needs be, I'll have to just get another 680 2GB.

[kavorka]

In Octane, you will have available VRAM equal to the lowest amount in your cards. SO, if you have a 2Gb and a 4GB card, Octane will see 2 GB available. This is because it needs to load everything into every card, so anything over 2GB would not be able to load into the smaller card.


Speed wise, your cards will scale perfectly, and they do not need to be the same card.
In the stand alone version, in the preferences, you can enable/disable cards. I sometimes do this as I also don't have a card just for display.

[gordonrobb]

Ah ok, so with the memory limit, does this mean that if I got a 4GB card, and assigned that as the only card Octane was using, that would work. Or does it know I have a 2GB card (even though it's not using it) and not work. Obviously this would only be for particularly big or complex scenes.

Also, (sorry for this) does the amount of memory affect the speed?

[kavorka]

If you only have the 4GB card turned on, it will use that 4GB. You may need to restart Octane, not sure.

VRAM has no effect on render speed.

[BorisGoreta]

I read somewhere on the forum that developers are trying to optimize the engine so it doesn't slow down GUI at all so you don't need to have a dedicated card. I hope I didn't dream that.

[kavorka]

I read somewhere on the forum that developers are trying to optimize the engine so it doesn't slow down GUI at all so you don't need to have a dedicated card. I hope I didn't dream that.

That is supposed to be in the 1.12 release, maybe next week. I think it allows you to use something like 90-95% of the GPU for Octane, freeing the rest for other usage. it will slow Octane down, obviously, but allow you to do other things.
I'm looking forward to trying it out, I wonder how much of the GPU needs to be freed up for me to continue modeling while I'm rendering... hmm

[Leonardo]

You can always use the integrated graphics of the CPU for display and dedicating all cards fully to Octane, if your CPU + chipset configuration allows for it.

[gordonrobb]

Was thinking that, but wouldn't that involve pluging display into main board video output, which would mean losing functionality of 2 displays and GPU for all other apps?