It'd be a whole lot easier to diagnose if we knew what the application was doing. And easier still if we could see the code.

The first thing you need to do is profile both and work out where the time is being used. Once you know that, it'll be easier to reason about the cause.

Thanks for the reply. As the the other Anonymous Monk said, the app is a mix of perl/xs/c and is difficult to profile on Windows (normally I would use valgrind on linux). I did try Very Sleepy, but nothing stood out. Can you recommend a profiler for windows?

The app itself mainly deals with numeric data. Lots of double datatypes in C structs, with data manipulation in C, with perl providing an 'API' to make things easy for the end user, so something like this: 

my $sum = $apple + $orange;

[download]
The $apple and $orange variables are objects (typically mapped to large double vectors), the vector calculation would be carried out in C etc.

While our performance benchmarks are representative of our real workloads, they are very broad in nature...and contain lots and lots of code... While all the tests perform worse, the ones that stand out most (ie, 80%+ worse) do create more perl/xs objects than typical, so perhaps that is where I should start looking?

In reply to Re^2: Our perl/xs/c app is 30% slower with 64bit 5.24.0, than with 32bit 5.8.9. Why? by Anonymous Monk
in thread Our perl/xs/c app is 30% slower with 64bit 5.24.0, than with 32bit 5.8.9. Why? by Anonymous Monk

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