What do G and C types mean in nvidia-smi?

Question

I have an open issue because I thought that my cuda code wasn't running in my GPU (here). I thougth that because I get a C in the type field of my process when I use nvidia-smi, but I see that my GPU-Util grows when I run my code so now I don't know if it is running in the cpu or gpu. Can someone explain to me what is the meaning of the C or G type, please? I found this: "Displayed as "C" for Compute Process, "G" for Graphics Process, and "C+G" for the process having both Compute and Graphics contexts." but I don't understand if it means that C is for CPU and G for GPU, because I don't know what "compute process" and "graphics process" are, or what differences are between them.

Answer 1

They are both for GPU.

• C = compute = CUDA or OpenCL
• G = graphics = DirectX or OpenGL

Answer 2

According to the man pages of Ubuntu defined here: https://manpages.ubuntu.com/manpages/precise/man1/alt-nvidia-current-smi.1.html

• C = Compute, which defines the processes that use the compute mode of Nvidia GPUs which use CUDA libraries, used in deep learning training and inferencing using Tensorflow-GPU, Pytorch, etc
• G = Graphics, which defines the processes that use the graphics mode of Nvidia GPUs used by professional 3D graphics, gnome-shell (Ubuntu's GUI environment), Games, etc for the rendering of graphics or videos
• C+G = Compute + Graphics, which defines the processes that use both the contexts defined above.

A developer document for nvidia-smi - NVIDIA System Management Interface program http://developer.download.nvidia.com/compute/DCGM/docs/nvidia-smi-367.38.pdf

If you want to have a deeper dive into the architectural components of the Nvidia Turing GPU, have a look at the whitepaper @ https://www.nvidia.com/content/dam/en-zz/Solutions/design-visualization/technologies/turing-architecture/NVIDIA-Turing-Architecture-Whitepaper.pdf

As a general rule, everyone working on a software stack that is as expansive as ML should have a good understanding of the hardware components they work on.