Quote - Paul can you confirm if the texture slots can be added up if you have two cards, for example in my case two GTX 580 each one with 3GB?

They are not added.  When you have 2 cards, the scene (simultaneously) gets loaded into both cards, and they both contribute to the render (effectively doubling your render speed).  So in your case, you have 3GB VRAM (which is plenty) and 64 RGB and 32 Grayscale texture slots.  The 600 series cards are capable of unlimited texture maps, however in order for Octane to be backwardly compatible with older cards, Octane has a limit on the 600 series cards of 144 RGB and 68 grayscale (plus another 20 HDR images) - so you can see the 600 series cards offer much more to the Poser user /IF/ you are working we very large scenes.  If your standard render is a couple of figures plus clothing plus a few props, you are unlikely to go near the 64 RGB limit - it's really the big environment props which use 100+ individual texturemaps where you will need to make the out-of-camera shot elements invisible to get into the 64 RGB texturemap limit.

Paul

 

I mostly want to use Octane to render animations of characters so I guess the 580s will be good enough.  What type of card should I use if I want to use a cheaper card for the OS, since I don't have onboard video.  I have a Zotac GT 430 2GB DDR3 with a measly 96 cuda cores that I can add to my third PCI-e slot, will that work?