[pypy-issue] [issue1528] I/O in pypy is up to 2x slower than CPython

Lefteris Stamatogiannakis tracker at bugs.pypy.org
Thu Jul 4 12:16:25 CEST 2013

New submission from Lefteris Stamatogiannakis <estama at gmail.com>:

Reading a file in pypy can be up to ~2x slower than CPython.

Antonio Cuni mentioned that it may be a problem with the low level implementation of pypy:

On 4/7/2013 9:12 am, Antonio Cuni wrote:
"Few days ago I discovered that there is an easy optimization for this. If you look at how 
str2charp & friends are implemented, you see that we do an RPython loop and copy char by 
By contrast, things like string concatenation are implemented using memcpy and are much 
faster (like 3-4 times, iirc)."

Example code:

f=open("text.txt", "w+b")
s="qwerty" * 10 + '\n'

for i in xrange(100000):

messages: 5905
nosy: estama, pypy-issue
priority: performance bug
status: unread
title: I/O in pypy is up to 2x slower than CPython

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