GPU memory issue/question

[dkreset]

so I've been digging around so much lately regarding this issue but I couldn't find anything useful so I'm hoping someone can help me out here.
I bought a GTX 660 with 3Gbs of GPU for octane. (I currently only have one card installed, have a second as a spare when I get a new power supply). Last night I was rendering a close up shots with some high res texture sitting at 4k, 9 maps total. When I loaded one more map at 4k it renders black. I soon realized that it was running outta memory to render that texture map because when I down rezed the image it rendered fine.

I checked my GPU information and noticed that there is only 640 mbs available for use but 3gbs in total of course. anyone has any idea how to dedicate more GPU memory to octane? Would installing a second card that works just for the monitor and everything else help with this? I read that it will help with windows navigation and what not but doesn't really explain anything based on this.

I hope it's not a case of my texture being too high because it will be quite the disappointment as more high quality renders in cinematics are sitting at 4k or higher. Doesn't seem very practical if Octane render can't handle a few 4k maps at render time ...

I will post a screen grab tonight when I get back to it. Thanks a lot guys!

[LudovicRouy]

I think your Textures are to big for a close up view, I divide the resolution when I want bigger render, and maybe you could lower it much if it's just a hdri that highlight your object, textures are the most memory consuming in octane

[LudovicRouy]

try to use procedurales textures if you can because they use very few memory, they just slow down the render a little because they are math fonctions

[mauricesteenbergen]

s Would installing a second card that works just for the monitor and everything else help with this? I read that it will help with windows navigation and what not but doesn't really explain anything based on this.

Yes, that helps because then all memory is reserved for Octane.
I did the same here, I first only had a GTX480 for both Octane and system, and there was always a couple of hundred MBs lost to my system, C4D, Chrome etc. Added an old 8800 GT for my system, and everything was faster.

Like you said, navigation is faster too, and your card can cool down between renders. Make sure to tweak your performance settings, in my case with the GTX480, it was never coming back into full performance mode (P0), had to put the card into "performance boost" instead of "powersaving" mode (NVIDIA control panel)

[dkreset]

thanks for the quick response. I understand that textures are the most memory consuming things in octane which is why I upgraded to a new vid card with 3Gb of GPU but at the moment only 640 mbs are available for me in Octane that's where I thought was ridiculous. So I guess what I'm looking for is a way to fully utilize the 3 gigs of GPU so I can dedicate them to my texture or else octane render becomes less useful to me imo. I had some experience working on a few cinematic assets in the past year and their textures easily go up to 8k for an eyebal for super close up shots. So I hope octane is able to provide me renders at the same caliber. If it's simply because my specs are too low and can't run the textures then I can go straight to an upgrade but it's using 1/5 of my GPU available which makes me scratch my head...

[dkreset]

s Would installing a second card that works just for the monitor and everything else help with this? I read that it will help with windows navigation and what not but doesn't really explain anything based on this.

Yes, that helps because then all memory is reserved for Octane.
I did the same here, I first only had a GTX480 for both Octane and system, and there was always a couple of hundred MBs lost to my system, C4D, Chrome etc. Added an old 8800 GT for my system, and everything was faster.

Like you said, navigation is faster too, and your card can cool down between renders. Make sure to tweak your performance settings, in my case with the GTX480, it was never coming back into full performance mode (P0), had to put the card into "performance boost" instead of "powersaving" mode (NVIDIA control panel)

ah! thanks a lot, I definitely needed the confirmation. Power supplies aren't cheap and I want to be making a worthy investment. I almost thought I wasted my money on the 3G GPU there lol So after switching to performance boost was it able to allocate the full amount of GPU? or there's still some of it being left out? I'm not quite sure how Octane uses the GPUs...

[FooZe]

Something other than the OS must be using the VRAM, ~2.5GB of VRAM is not a small amount...
Can we see your file -> preferences -> Cuda Devices? Maybe start closing applications until your VRAM becomes free to find out what is eating it.
A 4096x4096 texture takes about 65MB on the GPU, so you can have plenty of these if you get rid of whatever is using all your VRAM. They really shouldn't be a problem.

Thanks
Chris.

[dkreset]

hey fooze, thnx for the response!

so i tried it again tonight and more memory freed up. last night it went up to 650 mbs and just stopped there and from above that octane crashed a few times. Now it seems to be using the full extent of it, sitting at 700 mbs being used at the moment with more 4k textures loaded in...

this is the CUDA info however, maybe you could figure something out from this and tell me a little bit about how I'm managing this because not all of these make sense to me. Some tips to increase the speed of my render would be nice!

[itou31]

Hello,

I use 2x580GTX and have some question on the memory attribution to one or/and other GPU.
When I use all the memory (full red of textures), I have 2 GPU ok with the resolution 1200x600. But When I increase the resolution, one GPU failed, but octane continue to render, but slower.
The status go from white to orange. Does it mean that I lost some texture ? but the render continue ?
Thanks

[FooZe]

hey fooze, thnx for the response!

so i tried it again tonight and more memory freed up. last night it went up to 650 mbs and just stopped there and from above that octane crashed a few times. Now it seems to be using the full extent of it, sitting at 700 mbs being used at the moment with more 4k textures loaded in...

this is the CUDA info however, maybe you could figure something out from this and tell me a little bit about how I'm managing this because not all of these make sense to me. Some tips to increase the speed of my render would be nice!

The things you want to take note of are:
Total usable device memory - this is showing 2312MB which means that about 600MB is being used by something else (3d application or windows if you have your monitor plugged into this card).
Geometry - this is all the obj files
Image Textures and HDR textures - these are all the textures in the scene
Render Target Film - this is the place the final render is stored and increases when you increase the render resolution.

The speed of rendering is more related to kernel type, settings and scene optimization (light placement, using IES lights etc). How much VRAM is used has no direct impact on performance (other than your scene being more complex and therefore taking longer to render).

Hello,

I use 2x580GTX and have some question on the memory attribution to one or/and other GPU.
When I use all the memory (full red of textures), I have 2 GPU ok with the resolution 1200x600. But When I increase the resolution, one GPU failed, but octane continue to render, but slower.
The status go from white to orange. Does it mean that I lost some texture ? but the render continue ?
Thanks

The Render Target Film will be increasing in size and causing one of your GPU's to run out of VRAM (most likely this will be the one that you have your monitor plugged into as windows or other app's will use the VRAM of this one leaving less for octane). One of your GPU's will report a failure (out of VRAM) and octane will stop using it, hence the slower render.

Thanks
Chris.