Hello, I’ve been using blender for about a year now and I finally have a GPU for rendering in cycles. Now I don’t know a hole lot about GPU rendering but I saw that the graphics card that I have has 640 CUDA cores but it only renders with one thread. I don’t know if this is just how it is with GPU’s or if I did something wrong with the drive and tool kit for CUDA. I installed it on a computer running Linux Ubuntu 14.04 LTS and Blender 2.72b. Right now the GPU is rendering a scene with one thread as fast as my eight core CPU. If someone could clear up whether or not its just one thread or its a problem with the driver that would be great. Please and thank you.
Hi, it work as expected.
Internal it use all Cuda cores but for Cycles it is one device.
You should use at least 256x256 Tiles for GPU or Dimension /2 or /4 to get the best performance out of your GPU.
Cheers, mib
Ok thanks!
Hi there, i’m sory to say it’s not work as expected
I used to render with GPU on my thinkpad T530 laptop, and it has 4 tiles, and it’s truely much faster than CPU render.
Since i’ve installed ubuntu 14.04LTS on this laptop, GPU render only 1 tile and much slower.
I think the problem is from the Cuda installation!
Hope someone can solve this!
The same problem for me.
I just buy a new computer (before I never used GPU rendering due to my old Mac capabilities) : Ubuntu 15.04 ; GeForce GTX 970 ; i5-4590 (4 cores) ; 7,7 Gio RAM.
I use NVIDIA binary driver 346.59 and Blender form blender.org
GPU rendering is available and correctly fast, but only one thread is working at the same time.
I have to tell the first days uses of blender on this computer : I had 4 threads working in the same time, but I really don’t know why it don’t work now, but I know it’s possible.
I tried to re-install Blender, the NVIDIA driver, etc… but nothing worked.
Someone have an idea ?
GPU rendering with Cycles shows - and to my knowledge has always shown - one tile per GPU.
CPU rendering shows one tile per (real or virtual) CPU core.
Exactly, I have two GPUs so when I render it does 2 tiles, my CPU has 6 cores, so it will do 6 tiles.