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Re: I/O performance
- From: "Paul Richard Thomas" <paul dot richard dot thomas at gmail dot com>
- To: "Manfred Schwarb" <manfred99 at gmx dot ch>
- Cc: fortran at gcc dot gnu dot org
- Date: Thu, 20 Nov 2008 13:42:27 +0100
- Subject: Re: I/O performance
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Dear Manfred,
> character value*10000000
Using Cygwin, which tends to be a bit slower, I found a time of
9.6seconds, without optimisation.
Dividing the length of value by 10, this went down to 1.1seconds and
then to 0.2seconds on a further division by 10.
> Almost 5 seconds to read 20 Integer values,
> on a Core2 CPU! I was really shocked.
Don't be shocked, the problem is not the 20 integer values but the
size of the buffer 'value'. It looks as if the buffer is either being
zeroed or, more likely, a temporary is being used for the read.
Please file under Bugzilla as missed optimisation.
Thanks
Paul