Gpu setup with Octane+c4d on Mac Pro

[andresojeda]

Hi, I'm having issues understanding how to optimize the use of my graphic cards with octane.
I have two mac pros, one with two titanx cards and the other with two gtx 780 cards.
my question is related to the vram memory usage and priority. When I check both cards in the device usage window I loose about 1.5gb of memory.
So I uncheck one card and regain my memory. if this is the case and i'm going to work with one card only then should I setup my computer with one titans and one gtx 780 and
use the gtx 780 for the monitor and system and the titanx for rendering?
Will I loose a lot of rendering power just using one card? When I use one computer as slave then I'm using those cards completely?
Please help with these doubts.

[bepeg4d]

Hi andresojeda,
what happen is that VRAM is used by displays and you loose some of it.
Could you be more specific about your setup?
Do you use the one with Titans as master and the other as slave?
Which Titan and which 780 precisely?
How many display do you use with them?
I guess that the best thing should be to add a third single slot card for display only, like this old one:
http://www.ebay.it/itm/APPLE-MAC-PRO-Ge ... Sw7FRWVrmM
ciao beppe

[andresojeda]

Hi Beppe,
I use two titans in one machine and two gtx 780 in another. I'm thinking of making the same setup in both so 1 titan and one gtx 780.
my reasoning is to use the 780 for the screen and leave the titan solely for rendering.
is this a wise choice so that the titan will work full on rendering and the other card will split work with the system.
My other issue is the gram and the priority settings which are really confusing. When I click both cards as active I loose a lot of vram, a lot.
I haven't understood or felt the effect of the priority settings.
I normally use two screens to work is this an added issue? i connect both to one card leaving the other one free for render.
The third card is not a very good idea as the space in the Mac Pro is very tight and there would be heat problems and i use the void space to pass the connectors to my external power source for the second card.

Thank you

Andres

[andresojeda]

So now that I setup the titan and the gtx 780, when I pick both cards to render, octane goes to the 3gb of the 780.
If I use only the titan it uses the 12gb. When I render with both cards it renders faster of course but with the vram limitations.
I'll try with the other machine as a slave and see how it goes.

[bepeg4d]

Hi,
I have the GT 120 packed between two 780 from a long time now and it's a perfect solution for me, but I always leave the side panel opened
Have you already tried the new v3 alpha version?
it behaves differtly compared to v2, maybe it's better for you
ciao beppe

[andresojeda]

No Beppe, in fact where do I download the alpha v3?

[bepeg4d]

Hi andresojeda,
here is the link to the more stable standalone v3 alpha version:
viewtopic.php?f=33&t=52927
ciao beppe