Re: Increase WinXP/jre CPU usage?

Patricia Shanahan <>
Tue, 14 Nov 2006 08:58:45 GMT
Steve Brecher wrote:

It's nested loops enumerating cases; there's a computation for each case,
i.e., inside the innermost loop, and the computation results are

It should be possible to dual-thread it, e.g., one thread doing the odd
cases, so to speak, and the other the even ones. I could synchronize access
to the accumulation structures, or perhaps have two of them. For generality
maybe I can even N-thread it. I'll have to think about this...

Given trends in computer architecture, I suggest N-threading it while
you are about it. When you go to replace that computer, you may find
yourself getting something with multiple cores, each multi-threaded.

For reduction problems (problems that take a long vector and produce a
single answer, such as adding things up), it is generally better, if
permitted by the problem, to have an accumulator for each thread, and
only add them at the end. The less synchronization in the middle of the
problem, the faster it will go.

Consider organizing the work so that each thread operates on a
contiguous chunk of data, in case they get assigned to separate
processors with their own caches.

However, I would go for simplicity, within the at-least-dual requirement.


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