How to choose the optimal thread pool size for computations with a large number of resources?

The optimal size of the thread pool for computations depends on the number of available CPU cores and the nature of the tasks. For CPU-bound tasks (computational), it is usually recommended to set the pool size equal to the number of CPU cores or slightly more.

For example, if a device has 8 cores, the pool size can be set to 8 or 8-12 threads. This is because too many threads can lead to overhead from context switching and reduced performance.

In Android, you can get the number of available cores like this:

int cores = Runtime.getRuntime().availableProcessors();
ExecutorService executor = Executors.newFixedThreadPool(cores);

If the tasks are mixed (CPU + IO), you can increase the pool size, considering the IO wait time.

Summary:

• For purely computational tasks, the pool size ≈ number of cores.
• For mixed tasks, you can increase it, but with caution.
• It is important to profile the application and empirically select the size.