Latest update and still Houdini 17 doesnt support multi GPU acceleration specially when it comes to simulation tasks, but there is a trick that we can do to over come this partially.
As the title said, you can tell Houdini to use another GPU as an OpenCL accelerator and leave the main one for UI and display.
Why it is important? well normally when working with a project and having a couple of programs opened your GPU memory will be half full or lets say a minimum of 2GB will be utilized. So if you wanna use the same card to sim Flip or Pyro (specially) it's going to load the grid to the GPU and need every MB there and you will be downhearted to find that there is not enough.
Upgrading to a 12GB+ card is a solution but in the meanwhile and if you are on a tight budget and have another GPU hanging there then you will find you answer here.
The process is as simple as modifying Houdini environment file, let's start: - Open houdini.env (C:\Users\"user"\Documents\houdini xx.x) using a text editor.
- At the end add the following line (HOUDINI_OCL_DEVICENUMBER = 1)
In some cases you need to add the following line (HOUDINI_OCL_VENDOR=“NVIDIA Corporation”) for Houdini to pick up the specified gpu.
The numbering system starts with 0 (the main gpu) and then 1 (you second one).
Save the file and open Houdini, go to Help menu > About Houdini > Show details, then scroll down to check Opengl it should show your main GPU, go down more and you will find Opencl is assigned to the second one.
I personally tried it and it works like a charm, hope you found this blog helpful and see in another tip.