Thread vs ThreadPool

Question

What is the difference between using a new thread and using a thread from the thread pool? What performance benefits are there and why should I consider using a thread from

Answer 1

The .NET managed threadpool: -

• Sizes itself based on the current workload and available hardware
• Contains worker threads and completion port threads (which are specifically used to service IO)
• Is optimised for a large number of relatively short-lived operations

Other thread pool implementations exist that might be more appropriate for long-running operations.

Specifically, use a thread pool to prevent your app from creating too many threads. The most important feature of a threadpool is the work queue. That is, once your machine is sufficiently busy, the threadpool will queue up requests rather than immediately spawn more threads.

So, if you will create a small, bounded number of threads create them yourself. If you cannot determine up-front how many threads might be created (e.g. they're created in response to incoming IO), and their work will be short-lived, use the threadpool. If you don't know how many, but their work will be long-running, there's nothing in the platform to help you - but you might be able to find alternative threadpool implementations that fit.