Re: Increase WinXP/jre CPU usage?
Steve Brecher wrote:
Patricia Shanahan <pats@acm.org> wrote:
Steve Brecher wrote:
Patricia Shanahan <pats@acm.org> wrote:
...
Here's a suggestion for a cheap test:
1. Add, if the application does not already contain it, some
performance statistics collection keeping track of how much elapsed
time it takes to do a given quantity of the compute intensive work.
2. Run one copy of the application. Record the statistics.
Already done.
3. Run two copies of the application, simultaneously. Record the
statistics.
How important is (almost) exact simultaneity? Would starting one
manually via console, then another be sufficient? This would mean a
delay of several seconds; the run time is 3+ minutes. If not, it
would be reasonably easy to multi-thread the code if the the total
workload didn't have to be apportioned among the threads.
I would think that would be close enough. We are trying to tell the
difference between a throughput change that would justify programming
effort and a few percentage point change.
The single-job calculation takes about 185 sec. Running two of them
manually took 456 and 461 sec., with Task Manager reporting 49-50% CPU usage
for each. So the average of the two was 2.5x the single-job!
I would look at it in terms of throughput. Single thread does one job
per 185 seconds. Two jobs does about 2 jobs per 460 seconds = 1 job per
230 seconds.
The two job throughput is 230/185 = 1.24 times the single thread
throughput, a 24% gain.
You need to decide whether that is enough to justify the work of
parallelizing the job. However, I think you said you will be moving to
dual core, and the trend seems to be towards multiprocessing, so it
might be worth the investment even for a relatively small gain.
Patricia