GPU rendering in cycles

Hey guys,

So I’m working on a video project in cycles and I’m using the GPU to render. I just wanted to do a quick preview render and see how it was looking but each of the 6000+ frames takes approximately 15-20 seconds to render. I have the sampling set to 12 and everything on low resolution.

I’m wondering is this a typical render time for each frame? I’ll post an image to show what the scene is like.

I just wanted a very fast output to quickly see a preview. Do I have something set up wrong or is this usual? I see sometimes people render at 1000 samples or more so if I’m only at 12 then it just seems really slow. I have a GeForce GTX 680, 8 core processor, and 8GB of ram. I haven’t used cycles a lot so maybe I’m just expecting too much.

Thanks for any help/information.

Please ALWAYS supply an example .blend file with every support question.
Right now the only thing we know about the scene and your render settings is the sample count - that’s not really a solid basis for any kind of advice…

In user preferences > system you have enabled cuda and your video card in COMPUTER DEVICE?

Here is the .blend file I’m working with. Monday March 7, 2016.blend (834 KB)

You’re not rendering 12 samples. You have “Square Samples” checked, so you’re actually rendering 12 x 12 = 144 samples.

Make sure you use a decent tile size.
CPU rendering is faster with small tiles (e. g. 32 x 32 or even 16 x 16)
GPU rendering needs large tiles (e. g. 256 x 256)
You might want to use the Auto Tile Size addon for that.

You may want to increase your tile size - GPUs work better with 256x256. Also, you have square samples set, so you are rendering with 144 samples, not 12.

Also, I always render to an image file (png, tif, etc) and then combine them later in the video editor - that way you can render in batches, or just not worry if blender crashes.

Dammit, Ikari beat me to it :slight_smile:

Alright thanks for all of the help. I didn’t realize that the square sampling did that. I was just reading up on cycles and was reading about setting the tile size to 256 for the GPU so thanks again for the help there. As for the rendering to image; I do render to .png files but the save that I gave you guys was a test to see what it looked like. I was also reading about baking. Should I also be baking my file before I render it?
Thanks for the help. I’ll mess around with it and see if I can improve the render time.

Thanks guys, It’s so much better. Averaging just under 3 seconds.