The other interesting thing to think about: at what point do we beat the
same algorithm in C, and how hard would it be to parallelise the algorithm
in C with
those extra cores and beat C today! (Parallel Haskell redux)
Since I'm doing stupid benchmarks
anyway, why not this? I didn't use
pthreads though—I haven't
used that particular API in about a decade, and even then, I wasn't thrilled
Nope. Instead I used a Linux specific call—
clone(), wrote a
small function to wait for all the threads that were created, and basically
spent about five minutes making a
parallelized C-version of the Fibonacci sequence.
Granted, I had to do the parallelization explicitly, but it wasn't that
difficult to do.
The hard part was finding a quad-core box to test this on. Fortunately, I
know we have one at The Company (shhh—don't tell Smirk) and that's where I
spent most of my time on this—locating our single quad-core machine I could
test this on.
But find it I did. And yes, the program does run faster the more cores
that are thrown at it, but it's not a linear speed up:
A Parallelized Fibonacci Sequence calculation program
|# cores ||Runtime |
|1 ||0m31.468s |
|2 ||0m19.521s |
|4 ||0m17.234s |
It's interesting that it appears to be bottoming out rather quickly (and
these are average times over a few runs).
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