Stage Fright, or more on Performance Anxiety
Posted by Rick DeNatale Fri, 22 Dec 2006 17:19:00 GMT
Hmmmmm
I’ve been thinking a bit about the ramifications of the C++ vs. Python vs. Ruby benchmarking fud I wrote about in an earlier post
I’ve been looking at this from the point of view of how Ruby implements Arrays, digging deeply in to array.c, but I just stepped back and I noticed something which might or might not be important.
Besides using an Array rather than a linked list, the Baus Ruby benchmark doesn’t even do the same thing as the C++ one. In C++ the list is being used as a stack, items are added to the head of the list and removed from the head.
In the case of the Ruby benchmark, elements are inserted at the front of the Array using insert(0, obj), but removed using pop, which actually removes the last element. So instead of a stack we have a queue.
The Python code has a variation on the same problem, it uses append which adds to the end of the list, but del(0) which removes the first element.
Now I know that in benchmarking only performance matters, so I guess the old adage Make it work right before you make it work fast doesn’t necessarily apply.
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