What is the best GPU combo for Octane

[Witpapier]

GTX 590 3gb with a gtx 670 2gb or two GTX 670's 2gb in SLI??

[pixelrush]

Octane doesn't utilise sli.
To use cards together to best effect they should have the same size vram since the same data is loaded into each gpu.
A 590 is effectively 2x 580/1.5gb ie quite fast but not so much work space.
Ideally you should use a basic card for display purposes and some grunt cards dedicated to the rendering calcs.

[Witpapier]

what would you recomend I do?

[pixelrush]

Well it depends
What type of subjects are you rendering? Is it fairly simple scenes or heavy archviz stuff?
You need to make sure you have enough vram aboard as a workspace for your typical needs.
Also you need to look at your existing power supply to see what connectors and capacity it has to run these cards.
When Octane runs it utilises your cards to the max. but the CPU isn't that important.
Other things to consider are case cooling and you need sys ram of roughly 5 or 6x the vram of one card to fully utilise its capacity and without paging to disk while loading which is a definite retardation.
The number and arrangement of the pcie slots on the mobo is important in determining what you can actually fit in.
Some cases don't accommodate long cards either. If your mobo has integrated graphics you can make use of that instead of a basic disrete one for display while 'proper' cards do the cuda heavy lifting.
Fermi generation cards were/are relatively good performers in comparison to Kepler but Octane allows twice as many textures to be used with the later. Fermi generation also ran hot and loud generally. A lot of people still use them though. It seems as though there will be a Kepler refresh in coming months and that some cards (780?) will get a decent speedup and might be worth waiting for.
So there are a few things to be considered and traded off in making your best choice.
Maybe you could give us a few more details and we could provide some narrower options for you to think about.

[Witpapier]

I need guys with experience in this business to give me some sound advice. My current setup is I52500k with 16 gig ram and a Geforce gtx 670 2gig with a 750 watt psu. I am looking to get my render speeds up. now I need to get a addon card thats gonna help me the most in this regard. I can buy a GTX 590 3gig or another gtx 670 2gig. I know that the gtx 590 is faster and would by itself probably render at the same speed as two gtx 670. Ram would be split tho in two 1.5gig sections which is gonna limit me more. but I might get 9 ms/sec together with my gtx 670. where two gtx 670's might give me 6ms/sec. Im also wondering about the future Octane support for the newer Kepler cards with SM 5.0 capability, and if the performance would increase on the newer cards in the future, which would make the 2 x gtx 670's a safer long term option. I am rendering with the poser plugin for octane and rarely use 1000mb of vram, but I have run into trouble before in creating scenes with some added frills and stuff.

[pixelrush]

Hi,
Which model is your motherboard? Ideally you want to put a single slot width card in with whatever you choose just for the display. This will free up some vram space (especially useful if you end up with 1.5 gb effective vram being the least common amount between cards) and also make scene navigation more responsive
A 590 draws 365w and a 670 draws 170w, the i5 and other bits about 105w, and a basic card say 60w = 700w max so 750w might squeak in if its a good one considering the cpu and 3rd card wont be working hard although 850w might have been better.

[Witpapier]

Thanx for the reply. my mobo is a Intel dp67bg SLI board http://www.intel.com/content/www/us/en/ ... p67bg.html.

[pixelrush]

Hi again,
I see the mobo doesn't really offer any possibility for other than 2 double slot cards.
There is a spare PCI x1 slot there between them but it might be hard to find a suitable card for that. I see evga still market a 6200 for PCI but thats probably too old and driver wise now. This arrangement might be too slow even just for basic display purposes. It may or may not be able to used too ahead of the pcie slots for the graphics depending on the bios.
I think on that basis its probably better to go for another 2gb card in a second 670 although I suppose as an alternative you could trade in the 670 for another 590 and assign one of the gpu for display and use 3 for rendering but you would really need to upgrade your power supply to 1050w say. This latter solution would give you the best speed/responsiveness although you might find the 1.5gb limiting sometimes. Even though its 1.5gb it probably works out about the same effective space because some of the 2gb you have currently will be used by windows for the regular display. Overall this split of 2x590 duties could be the neatest solution. Be careful to make sure your case will fit them though. The lower pcie slot seems to be high enough up the board not to cause a problem with clearance to the bottom.
The only real improvement you are passing up on with Fermi rather than Kepler generation as far as Octane use goes is the increase in texture numbers afforded and of course you would want extra vram for those. This is why people are looking for 3 and 4 gb variants of cards.
I guess its up to you to decide how demanding of work space your renders are likely to be into the future. If its going to remain about 1gb then using 590 might be fine and its going to render quite quickly, somewhere about 11.5ms/s I would think.
I am not sure what Otoy have in the pipeline in regard of capability that might only operate on Kepler but you are probably safe. Possibly the next jump in capability won't arrive until Maxwell generation and I wouldn't anticipate any immediate redundancy.
Just exploring all options/ tossing ideas around for you.
HTH

[FrankPooleFloating]

I haven't seen many folks talk about resolution when discussing which cards and how much vram... If, like myself, you are finding that you need to render up to spread ad size (17x11 @ 300 - 5100x3300) you are going to need as much vram as you can get your filthy paws on - and perhaps not be as concerned with your renders taking another minute or two to render. This is certainly something to consider. If you know that you will never need to render up to 5000 pix wide, for instance, then you may very well be okay with 1.5GB or 2GB... or less.. I have done pretty well with 1GB cards when not in super-duper-hi-res mode.

Ultimately, I am going to need to have at least 2.5GB or 3GB in each card I end up with in next machine. For the two spreads that I have had to render thus far, I ended up having to do them at around 4k and scaled in PS... fortunately, Octane scales better than anything I have ever seen.

[badmilk69]

two 670´s with 4gb each!