On Tue, 2009-09-29 at 09:08 -0700, Matt wrote: > So, using mytime2 with the myavgtime macro gives average execution > times for the expression (+ 1 2 3) of 2 to 3 times longer than when > using mytime1. Why is this? Does the JIT optimize differently with all > those println's when using mytime2? (Kind of "quantum mechanics-y" - > observing what's going on changes it.)
Output is painstakingly slow in all languages I've ever dealt with (I first noticed it in C). Most of the time it isn't noticed because there's a lot of other non-trivial stuff going on. Here's a comparison of a tight loop in C that does a printf vs one that doesn't (1,000,000 iterations of a simple calculation): With printf: real 0m23.534s user 0m0.396s sys 0m3.232s Without printf: real 0m0.018s user 0m0.012s sys 0m0.000s and for comparison, the same in Python: With print: real 0m25.879s user 0m2.172s sys 0m3.300s Without print: real 0m0.596s user 0m0.532s sys 0m0.052s Notice that with console output, the Python program is almost as fast (or as slow) as the C version =) In short, you've taken something that was originally CPU-bound and made it I/O-bound. Regards, Cliff --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
