Python / Socket speed

[msj@infoserv.dk]

Seems like sockets are about 6 times faster on OpenSUSE than on
Windows XP in Python.

http://pyfanatic.blogspot.com/2007/02/socket-performance.html

Is this related to Python or the OS?

/MSkou

[Richard Brodie]

Re: Python / Socket speed


<msj@infoserv.d kwrote in message
news:1172501644 .228475.57540@a 75g2000cwd.goog legroups.com...

Seems like sockets are about 6 times faster on OpenSUSE than on
Windows XP in Python.
>

http://pyfanatic.blogspot.com/2007/02/socket-performance.html

>
Is this related to Python or the OS?

It's 6 times faster even when not using Python, so what do you think?
It's probably 'just' tuning though, the default window sizes are in the
same ratio.

[Paul Boddie]

Re: Python / Socket speed

On 26 Feb, 15:54, "m...@infoserv. dk" <m...@infoserv. dkwrote:

Seems like sockets are about 6 times faster on OpenSUSE than on
Windows XP in Python.
>

http://pyfanatic.blogspot.com/2007/02/socket-performance.html

>
Is this related to Python or the OS?

>From the output:

TCP window size: 8.00 KByte (default)
TCP window size: 49.4 KByte (default)

I don't pretend to be an expert on TCP/IP, but might the window size
have something to do with it?

Paul

[casevh@gmail.com]

Re: Python / Socket speed

On Feb 26, 7:05 am, "Paul Boddie" <p...@boddie.or g.ukwrote:

On 26 Feb, 15:54, "m...@infoserv. dk" <m...@infoserv. dkwrote:
>

Seems like sockets are about 6 times faster on OpenSUSE than on
Windows XP in Python.

>

http://pyfanatic.blogspot.com/2007/0...rformance.html

>

Is this related to Python or the OS?
From the output:
TCP window size: 8.00 KByte (default)
TCP window size: 49.4 KByte (default)

>
I don't pretend to be an expert on TCP/IP, but might the window size
have something to do with it?
>
Paul

Tuning the TCP window size will make a big difference with Windows XP
performance. I'm more curious about the original script. Either the
test was against the loopback address, or he has a very impressive
netork to sustain 1.8Gbit/s.

casevh

[John Nagle]

Re: Python / Socket speed

Richard Brodie wrote:

<msj@infoserv.d kwrote in message
news:1172501644 .228475.57540@a 75g2000cwd.goog legroups.com...
>

>>Seems like sockets are about 6 times faster on OpenSUSE than on
>>Windows XP in Python.
>>
>>http://pyfanatic.blogspot.com/2007/0...rformance.html
>>
>>Is this related to Python or the OS?

>
>
It's 6 times faster even when not using Python, so what do you think?
It's probably 'just' tuning though, the default window sizes are in the
same ratio.

Sockets and pipes are a terrible way to do local interprocess
communication, but it's what we've got. The problem is that what you
want is a subroutine call, but what the OS gives you is an I/O operation.
If you want to see it done right, take a look at QNX messaging. QNX
does everything, including I/O and networking, via its interprocess
communication message passing system. There's the cost of one extra
copy for every I/O operation, but you don't notice it much in practice.
I've run 640x480x15FPSx2 4bits video through QNX messaging and only used
2% of an 1.5GHZ x86 CPU doing it.

John Nagle

[Paul Rubin]

Re: Python / Socket speed

John Nagle <nagle@animats. comwrites:

Sockets and pipes are a terrible way to do local interprocess
communication, but it's what we've got. The problem is that what you
want is a subroutine call, but what the OS gives you is an I/O operation.

Using TCP sockets is ridiculous but Unix domain sockets aren't that
bad. There's also mmap or shm.