[Python-Dev] 2.5a1 Performance

[Benji York]

Jeff Epler wrote:
> I'm not trivially able to try a 32-bit build, but for my system it
> appears that 2.5 is moderately faster than 2.4 when built with all the
> defaults.

OK, this prompted me to question my sanity.

Being on a laptop the default is to do frequency scaling (different 
speeds depending on CPU load).  When running pystone I've always seen an 
initial run that was much slower than subsequent runs, so I'd run 
several and throw out the first few.  This gives a max of 35k pystones 
with 2.4.2 and 30k with 2.5a1.

I decided to force the CPU freq. to the maximum (1.4 GHz) and remeasure. 
  2.5a1 reported the same pystones (30k) and, to my surprise, 2.4 
reported 31k (about 5k *less* than with freq. scaling on).  So there 
seems to be some interaction between frequency scaling and pystones.

Benchmarking is hard, let's go shopping!
--
Benji York