OTOY Forums

Hey guys, ive been searching all over the internet for questions and answers regarding video cards to buy, prices vs speed vs vram.

Im looking at either a 780ti 3gb, a780 6gb because of their price and performance factor and then I could stack more of these later or maybe even 12gb titan z. The reason why i may want to get 6gb is so that when I start stacking video cards, I already have a 6gb so this card will be useable.

The main question I cant seem to find, is what kind of scenes make octane go over the video cards vram, with and then without the out of core textures feature. If anyone could supply some sample scene pictures or something so I can decipher what my limitations would be and then be able to make a more educated decision if I need to buy a 6gb cards or even 12gb to stack onto.

Also, whats the best cloud render farm to use with octane. And do the prices start to get high? I cant seem to find one that helps me calculate properly.

Thanks
-Adam

For the most part I think it's image textures that will use the most vram on your GPU. Polygons don't appear to use the same amount of vram as images do, which makes sense. Octane allows you to use "out of core" memory (system memory) to store texture images, but you get a slight speed penalty from using it. With a 6Gb GPU I don't think you need to worry too much, unless your scene has 40 to 50 million polys and/or many Gbytes of image textures.

FYI: A Titan Z is a dual GPU card so each GPU has access to only 6 Gbs of vram and Octane will see it as two 6Gb cards.

Jason

And not to forget that very large resolution eats vram

rappet wrote:And not to forget that very large resolution eats vram

... in v2, but this is no more an issue with v3 since the frame buffer has been moved from VRAM to the system RAM leaving a lot more space on VRAM, especially for render passes
Another great plus of v3 is that there is no more the 19m poly count limit, so you can fill the free VRAM with super high poly count, just take in mind that you need extra system RAM for the geometry preparation to be sent to GPUs.
Octane v2 users can already download and use v3 with all this new features
ciao beppe

So with all these features.. will a couple of 780ti cards with 3gb have an issue? And if theres an issue, whats an example scene that it wouldnt be able to do..

also I just talked to somebody i might buy 2 780ti cards today, and he said that windows 10 can stack vram, so no more limitation to the lowest vram card.. However will this translate to octane render? like was it a windows, nvidia and/or render engine limitation to begin with??

Just jumping in with my 2 cents. Forget 3GB, you want at minimum 6GB. I went from having a 3 to 6 GB cap on my cards and never looked back. Good luck!

It really depends from your personal everyday workflow, geometry complexity, total number of texture, resolution and depth. With v3, the frame buffer is no more on VRAM, the texture could be moved to RAM with the out-of-core feature and there is no more the polygon count limit. In other words, if you have enough system RAM, there is still a lot that can be done with 3GB of VRAM
ciao beppe

Okay so how do I know what to choose here. Because if I buy one and need to stack them, im supposed to get the same amount of vram on other cards. Seems like 3gb can do a lot, but what kind of scene cant 3gb do is the question. Any examples?

Hi,
I guess that we can see in this way, if you want to render with hi res texture and full power, go for the maximum of VRAM that you can get. Anyway there is always space for optimisation like reducing the texture resolution, or reusing the same texture in multiple channels, or moving the texture into RAM with out-of-core option (reducing the calculation power of 10-20%), or with large use of instances to reduce the geometry weight.
To give you some numbers:

• • a single RGBA 8k x 8k texture can take up to 527 MB of VRAM, since all the textures are loaded uncompressed on GPUs.
• • 1 million polygons mesh can take up to 140/180 MB of VRAM.

I think that is a good idea to have at least 32 GB of system RAM for the future
ciao beppe

Okay so here are my options. Since Im planning on building my own gpu render farm. I was thinking of starting with 1 GPU then adding on as I feel needed.
I was looking at these options, and now considering what has been discussed in this thread, here goes what im thinking:

Right now I only have 8gb RAM, 6 core xeon CPU. I bought this HP Z600 workstation for $600 refurbished as I needed a newer PC with windows to just even try out these GPU render engines with CUDA.
I may buy a new computer. But im thinking that this computer is enough because when I am going to stack GPUs, im going to run a PCIE splitter: http://amfeltec.com/products/gpu-oriented-cluster/. Need to get power supplies as needed. And maybe I can upgrade my computers RAM.
With that being said here are the options Im going to use with the above computer and pcie splitter. Start with 1 gpu then stack same gpu as needed. Up to 8 if I really feel like I want/need to.

Option 1: gtx 780ti 3gb VRAM - $450 each
Start with 1 gtx 780ti 3gb VRAM.
With this option as I stack GPUs, I would be able to use out of core texture feature with reduction in render speed, but Im still using multiple GPUs so the question is whats better price. To go with more VRAM, or less VRAM.
Im going to get gpus refurbished as I dont agree with buying new due to depreciation on computer technology.
http://www.amazon.com/gp/offer-listing/ ... ition=used GTX 780ti - $450 each

Option 2: Titan X -
-12 gb vram
- $1100 each
Octane Bench: 126
start with 1 titan x then stack.
http://www.amazon.com/gp/offer-listing/ ... ition=used, price $1000 used and around 1100 new. very close.

option 3: Titan Z
- 12 gb vram
- 1300 each
- Octane bench: 174
stack titan z - has 2 gpus per card. Is the limit 6gb vram or 12gb vram with the titan z?
And this card I would have to stop at 4 gpus since Im pretty sure windows cant recognize higher than 8 gpus.
http://www.amazon.com/gp/offer-listing/ ... ition=used

option 4: gtx 980 ti
- 6gb vram
- $649.99 each
- Octane Bench: 125
start with 1 then stack as needed,

option 5: gtx 780 6gb vram edition
-6gb vram
- Price used: $450
- Octane bench - 84
start with 1 gtx 780 6gb vram. then stack as needed:
http://www.amazon.com/gp/offer-listing/ ... ition=used

option 6: gtx titan
- 6gb vram
- Price used: $600 each
- octane bench - 85
start with 1 then stack.

option 7: gtx 980
- 4gb vram
- Price used and new around 450 to 500.
- Octane bench - 97
I never thought of using a gtx 980 but now seeing the octane bench 4gb vram higher than 3gb vram gtx 780ti. and price at 500 new. This card is interesting.?.


I cant decide. lol. what would you guys do considering I need absolute photorealism, high resolution renders, shooting in 4k video..etc.. what best price vs value here. What would you choose? Or would you mix different kinds of video cards as needed.. I dont know.. let me know what you would choose.