CODEWITHSUNDEEP
windowsmultithreadingthreadpooliocp
Summer
Summer

Reputation: 209

What is the relation between number of thread and number of processor cores？

I am writing a server application that is thread pool based(IOCP). But I don't know how many threads are appropriate. Is the thread number associated with the number of processor cores?

Upvotes: 2

Views: 88

Answers (2)

usr
usr

Reputation: 171178

If your work items never block, use threads = cores. If your threads never need to be descheduled you can max out all cores by creating one thread per core.

If your work items sometimes block (which they shouldn't do much if you want to make best use of IOCP) you need more threads. You need to measure how many.

Upvotes: 2

cluemein
cluemein

Reputation: 882

Multiple threads make up a process, and the number of threads is not dependent on the number of cores. A single core processor can handle a multi-thread process using various scheduling schemes. That said, if you have multiple cores on your processor, you can have different threads run concurrently. So to run multiple threads at the same time, you need multiple cores, but to run multiple threads, but not necessarily simultaneously (can seem simultaneous though), you can use a single core by implementing a scheduling system.

Some useful wiki pages for you:

http://en.wikipedia.org/wiki/Computer_multitasking

http://en.wikipedia.org/wiki/Thread_%28computing%29

http://en.wikipedia.org/wiki/Input/output_completion_port

http://en.wikipedia.org/wiki/Scheduling_%28computing%29

http://en.wikipedia.org/wiki/Thread_pool_pattern

Upvotes: 0

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