I recently upgraded from CUDA 7.5 to CUDA 8.0 on my Ubuntu 14.04 LTS machine for one project.
Later I returned to working on an older project that makes use of the StereoLabs ZED driver (V1.1.0) but it turns out that this driver requires CUDA 7.5 and won’t work with CUDA 8.0
Unfortunately I removed CUDA 7.5 after the upgrade to 8.0.
The latest ZED driver that is compatible with CUDA 8.0 is only available for Ubuntu 16, and it doesn’t work on Ubuntu 14.04 LTS (I tried).
It seems I am looking at two options: either go to Ubuntu 16, or somehow get CUDA 7.5 back on my machine.
I’d like to hold off upgrading my OS for now.
Is it possible to install CUDA 7.5 again, next to the existing installation of CUDA 8.0 and if so, how should I go about it?
Certainly if you use the runfile installer method, the CUDA 7.5 installation will drop in alongside the CUDA 8 installation and not disturb it (they will be in separate directories).
You should pay attention carefully to the prompts offered you during install.
Select no when prompted to install the driver from the CUDA 7.5 runfile installer. Keep your CUDA 8 installed driver. It will work with CUDA 7.5
Select no when prompted to update the symlink for /usr/local/cuda (unless you want to switch the default config from CUDA 8 to CUDA 7.5)
When you want to actually switch your machine behavior from CUDA 8 to CUDA 7.5, you will need to modify the PATH and LD_LIBRARY_PATH env variables accordingly.
If you previous CUDA 8 install was via runfile installer, this should work fine. I use this method regularly. If you previous CUDA 8 install was via package manager method, I think this should still work but I don’t typically do that.
it’s probably also possible to do side-by-side install using only package manager methods, but I don’t have a set of instructions handy for that.
“When you want to actually switch your machine behavior from CUDA 8 to CUDA 7.5, you will need to modify the PATH and LD_LIBRARY_PATH env variables accordingly.”
How would you do this and also, can this be done when running CUDA 8 based codes and CUDA 7.5 based ones separately or simultaneously on the same machine?