Re: [xep-support] Different performance on different systems

From: David Tolpin <>
Date: Fri Sep 02 2005 - 06:36:15 PDT

> What sort of environment are you running XEP in? Is it running
> inside a Webapp, from commandline or an embedded java application?
> We found XEP doesn't scale across multiple CPUS in a multi-threaded
> java application. Others have reported the same on this list.
> Adding more CPUs actually makes the performance worse!!!!!!
> Perhaps the machine which you say is superior has 2 CPUs versus 1
> for the machine which yields better performance.

Hi Chris,

in the old code of XEP there was code causing contention; I believe
this code has been removed long ago. My belief is confirmed by a four-
CPU box showing linear increase in performance with the number of
threads. In any case, going from one CPU to two cannot impact the
performance on the order of 10 times; in fact, 2 CPUs were never
enough for contentions.

However, the original poster is complaining about non-buffered output
in the PDF generator of an old version of XEP, a version which is 1,5
years old now; and many bugs have been fixed since that time. Most
probably, the decrease in performance is caused by the target file
location being a network drive. That issue had been dealt with a long
time ago.

The recommendation is to make sure the problem goes away with the
current version, and to upgrade.

David Tolpin
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Received on Fri Sep 2 06:59:57 2005

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