Camera connection time is long

Problem

The camera takes a long time to establish a connection to the PC the first time it is connected to in a process.

Cause

OpenCL kernels are built for the specific hardware the camera is connected to, which is unknown until the camera establishes a connection to the PC. Building these kernels takes up a significant amount of the total connection time, and happens the first time the camera is connected to in a process.

If the process is kept alive (more specifically the Zivid application), then the kernels do not need to be rebuilt.

Solution

The kernels can be cached to avoid having to rebuild them every time you connect to the camera. Note that it still will be slow the first time it is connected to, but fast for every connect afterwards. Follow the instructions for your specific hardware.

Upgrade your Intel drivers to the newest available version to allow caching of the OpenCL kernels using the Intel Driver & Support assistant.

If upgrading your Intel drivers did not resolve the issue, you may manually allow caching (experimental). Follow the dropdown below for further instructions.

Manually enabling caching (Experimental)

This method is considered deprecated and experimental by Intel Graphics Compute Runtime, but is a temporary solution until your drivers get updated. Be aware of the mentioned limitations of cl_cache for Windows in the above link, and consider this only for non-production setups.

  1. Create a folder where you want to store the cached kernels, e.g. in %LOCALAPPDATA%/NEO/neo_compiler_cache

  2. Add a new environment variable cl_cache_dir and set its value to the path of cache folder, e.g. %LOCALAPPDATA%/NEO/neo_compiler_cache

You may have to restart your computer for the changes to take place.

Most NVIDIA GPUs and drivers should have caching on by default. If you are still experiencing slow connection times, try updating to the latest drivers for your NVIDIA GPU.

Upgrade your OpenCL drivers to the newest available version to allow caching of the OpenCL kernels.

sudo apt update && sudo apt upgrade intel-opencl-icd

If the latest version in the repositories is not sufficient, you can use the latest released package from Intel.

If upgrading your Intel drivers did not resolve the issue, you may manually allow caching. Follow the dropdown below for further instructions.

Manually enable caching

  1. Create a folder where you want to store the cached kernels, e.g. in $HOME/.cache/neo_compiler_cache

  2. Add a new environment variable cl_cache_dir and set its value to the path of the cache folder, e.g $HOME/.cache/neo_compiler_cache

mkdir $HOME/.cache/neo_compiler_cache
export cl_cache_dir=$HOME/.cache/neo_compiler_cache

Caching should now be persistent for the current session.

Most NVIDIA GPUs and drivers should have caching on by default. If you are still experiencing slow connection times, try updating to the latest drivers for your NVIDIA GPU.