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Editorial Team
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Asked: 2026-05-14T04:57:48+00:00

I have a program that starts up and creates an in-memory data model and

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I have a program that starts up and creates an in-memory data model and then creates a (command-line-specified) number of threads to run several string checking algorithms against an input set and that data model. The work is divided amongst the threads along the input set of strings, and then each thread iterates the same in-memory data model instance (which is never updated again, so there are no synchronization issues).

I’m running this on a Windows 2003 64-bit server with 2 quadcore processors, and from looking at Windows task Manager they aren’t being maxed-out, (nor are they looking like they are being particularly taxed) when I run with 10 threads. Is this normal behaviour?

It appears that 7 threads all complete a similar amount of work in a similar amount of time, so would you recommend running with 7 threads instead?

Should I run it with more threads?…Although I assume this could be detrimental as the JVM will do more context switching between the threads.

Alternatively, should I run it with fewer threads?

Alternatively, what would be the best tool I could use to measure this?…Would a profiling tool help me out here – indeed, is one of the several profilers better at detecting bottlenecks (assuming I have one here) than the rest?

Note, the server is also running SQL Server 2005 (this may or may not be relevant), but nothing much is happening on that database when I am running my program.

Note also, the threads are only doing string matching, they aren’t doing any I/O or database work or anything else they may need to wait on.

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1 Answer

  1. Editorial Team

    Without seeing the actual code, it’s hard to give proper advice. But do make sure that the threads aren’t locking on shared resources, since that would naturally prevent them all from working as efficiently as possible. Also, when you say they aren’t doing any io, are they not reading an input or writing an output either? this could also be a bottleneck.

    With regards to cpu intensive threads, it is normally not beneficial to run more threads than you have actual cores, but in an uncontrolled environment like this with other big apps running at the same time, you are probably better off simply testing your way to the optimal number of threads.

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