# [XeTeX] xetex memory usage

Wed Dec 17 00:36:51 CET 2008

Jonathan Kew пишет:
> On 16 Dec 2008, at 19:53, basketboy at bk.ru wrote:
>
>> Hello,
>>
>> I'm using MiKTeX 2.7 and xetex(xelatex) integrated in it. OS:
>> Windows XP
>> SP3.
>>
>> My question is about memory usage of xetex. I've noticed that when I
>> compile tex document, though this:
>>
>> \documentclass{article}
>> \usepackage{fontspec}
>> \setmainfont{Arial}
>> \begin{document}
>> The quick brown fox jumps over the lazy dog.
>> \textbf{The quick brown fox jumps over the lazy dog.}
>> \emph{The quick brown fox jumps over the lazy dog.}
>> \end{document}
>>
>>
>> I see that it uses at least 130MB of RAM to generate pdf. So if for
>> example I'm going to use xetex to generate pdf reports via webpage it
>> can cause memory overusage. For example if 10 people start to generate
>> pdfs simultaneously then 1300Mb of RAM will be used and it can cause
>> the
>> problems. We run into this problem already (with much more complex tex
>> documents) and server with 512 MB of RAM and it was overloaded.
>>
>> So my questions are the following:
>>
>> 1. Is this problem related with xetex or maybe fonts loading into
>> memory? If it is not related to xetex then sorry, I'll try to find
>
> The RAM footprint is much larger than standard 8-bit TeX because many
> internal tables have been expanded to cover the full Unicode range of
> characters -- approximately one million, as compared to 256
> characters. Using over 100MB is not generally a problem on modern
> hardware; much of this memory is not actively used in a typical run,
> and so virtual memory systems need not even keep it in real RAM, but
> it does get allocated at startup.

Thanks a lot for explanation.
>
>> 2. Is it possilbe to reduce RAM consumption in this case?
>
> Not with the existing program. Many of the internal arrays could be
> made much smaller by using a smarter "sparse array" implementation
> instead of simple flat arrays. This has not been a priority for me, as
> users do not normally need to run large numbers of xetex processes in
> parallel, but if someone wants to provide such a patch it would be
> welcome.
>
> Actually, you could reduce the RAM footprint quite a bit by reducing
> various parameters in texmf.cnf (for TeX Live; I don't know if MikTeX
> uses a similar configuration file), as the default settings (at least
> with TL) are extremely generous, and most documents can be processed
> within much smaller limits.

Hmm. Intersting. Can you please suggest some parameters for example in
texmf.cnf which can reduce RAM footprint?

> JK
>
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