[Python-Dev] Where the speed is lost! (was: 1.6 speed)

Christian Tismer tismer@tismer.com
Tue, 25 Apr 2000 20:12:39 +0200


Jeremy Hylton wrote:
> 
> The performance difference I see on my Sparc is smaller.  The machine
> is a 200MHz Ultra Sparc 2 with 256MB of RAM, built both versions with
> GCC 2.8.1.  It appears that 1.6a2 is about 3.3% slower.
> 
> The median pystone time taken from 10 measurements are:
> 1.5.2  4.87
> 1.6a2  5.035
> 
> For comparison, the numbers I see on my Linux box (dual PII 266) are:
> 
> 1.5.2  3.18
> 1.6a2  3.53
> 
> That's about 10% faster under 1.5.2.

Which GCC was it on the Linux box,
and how much RAM does it have?

> I'm not sure how important this change is.  Three percent isn't enough
> for me to worry about, but it's a minority platform.  I suppose 10
> percent is right on the cusp.  If the performance difference is the
> cost of the many improvements of 1.6, I think it's worth the price.

Yes, and I'm happy to pay the price if I can see where I pay.
That's the problem, the changes between the pre-unicode tag
and the current CVS are not enough to justify that speed loss.
There must be something substantial.
I also don't grasp why my optimizations are so much more
powerful on 1.5.2+ as on 1.6 .

Mark Hammond pointed me to the int/long unification.
Was this done *after* the unicode patches?

ciao - chris

-- 
Christian Tismer             :^)   <mailto:tismer@appliedbiometrics.com>
Applied Biometrics GmbH      :     Have a break! Take a ride on Python's
Kaunstr. 26                  :    *Starship* http://starship.python.net
14163 Berlin                 :     PGP key -> http://wwwkeys.pgp.net
PGP Fingerprint       E182 71C7 1A9D 66E9 9D15  D3CC D4D7 93E2 1FAE F6DF
     where do you want to jump today?   http://www.stackless.com