Out of Core Textures - Any downsides?

[Daniel_Ward]

Hi Guys,

I'm learning how to use Octane for ArchVis working with the ArchiCAD Plugin. After a bit of testing we've brought a first licence and I'm setting up a library of materials etc for the office to use.
Currently I'm using a GTX980 4Gb and a GTX660 2Gb on my home PC for doing the testing and using "Out of Core" textures as the 2Gb on the GTX660 gets full pretty quickly. I haven't observed any issues with this so far and the performance seems fine.
So in looking to put together some new PC's for the office that will run Octane I'm trying to work out if there are likely to be any issues with putting 3-4x GTX970's and using the Out of Core textures option of GPU RAM is an issue, rather than going for 2x GTX980Ti 6Gb cards?

Cheers, Dan.

[roeland]

There's two issues to look out for:

1. The performance will be slower.
2. The memory used for out-of-core textures is not available to other applications. This may be important if other applications need a lot of memory (like 3D modelling applications)

A lot depends on the scenes you're rendering, and your hardware setup.

Octane only allocates out-of-core textures when needed. If so, Octane displays a second (coloured) bar under the render viewport to indicate how much RAM is in use.

--
Roeland

[Daniel_Ward]

Hi Roeland,

we're currently looking at i7 6700K CPU's with 16Gb DDR4 RAM, the motherboard will depend in part on how many PCIe slots we end up needing.
Looking at Octane Bench, 4x 970's should be around 25% faster than 2x 980Ti's (for less money), but we'd need to consider whether that 25% performance margin would still maintained when we are in an "Out of Core" rendering scenario.
I wouldn't expect users to be producing 'final renders' while still working in ArchiCAD, so I doubt the RAM sharing between applications will be an issue for us, just performance while rendering in Octane.

Cheers, Dan.