# How to expand TeX's “main memory size”? (pgfplots memory overload)

I'm compiling one pretty simple LaTeX file with few dozen of pgfplots. Now, I can compile part by part, but am unable to compile it all at once. I really need good precision for all those plots (noise plots) and would like to avoid decimating graphs more. When I run compile, I get this error message:

[...] TeX capacity exceeded, sorry [main memory size=3000000].


Is there a way to avoid this message somehow? How am I supposed to use pgfplots if I can't plot couple dozen of figures with it without having TeX overloaded? How to expand TeX memory size, please?

• One simple way of making tikz-figures created by matlab2tikz smaller is to use the command cleanfigure in Matlab, before using matlab2tikz. I got this advice from a colleague recently. – Lars Abrahamsson Oct 14 '18 at 17:18

The pgfplots package can be particularly heavy on TeX's memory, especially if you are creating plots with lots of data points. Indeed, there is a section in the pgfplots manual about expanding TeX's memory. However, that does not mean that expanding TeX's memory is the best solution. Instead, I would recommend using the 'externalization' approach (section 7.1 of the pgfplots manual).

The idea of externalization is to compile each plot as a separate TeX job. This leads to a graphic which can be used in the main job. Thus each plot has its own memory requirement, separate from all of the other plots. This usually avoids needing to make TeX's memory bigger. At the same time, the resulting files can be kept between TeX runs, which will speed up compilation for the second and subsequent runs. The latest version of the externalization system needs you to do two things. First, you put

\usepgfplotslibrary{external}
\tikzexternalize


in your preamble, to turn the system on. Secondly, you will need to enable 'shell escape'. This is done at the command line by adding the -shell-escape switch:

pdflatex -shell-escape <filename>


The same can be done in LaTeX editors: there is usually a place in the settings for this type of thing. I'll just add that shell escape does has some security implications: use only with documents that you trust!

• I should probably say that I saw it coming. I had the feeling that "expanding the memory size" is not the answer, and externalization works flawlessly - plus, every following pdflatex run is ridiculously faster! Thanks! ...I should only find a way now to forward -shell-escape from rubber --pdf command that I'm using to pdflatex... – user1996 Dec 30 '10 at 9:59
• Also, try the lualatex compiler which appears to dynamically allocate more memory if it needs it. – Sharpie Apr 20 '11 at 4:44
• For everyone wondering why their images won't be updated after re-running pdflatex using the -shell-escape option: For every tikzpicture an extra .pdf file is created. Either delete the file, so it will be recreated next time you run pdflatex or put a \tikzset{external/force remake} somewhere in your document. – Lars Jun 6 '13 at 15:49
• I tried this, but i get an error: ! Package tikz Error: Sorry, the system call 'pdflatex -shell-escape -halt-on-e rror -interaction=batchmode -jobname "chap_naturalite-figure0" "\def\tikzextern alrealjob{chap_naturalite}\input{chap_naturalite}"' did NOT result in a usable output file 'chap_naturalite-figure0' (expected one of .pdf:.jpg:.jpeg:.png:).. Tried to delete the existing files and force remake but it does not change the problem. – Alexandre Willame Sep 30 '14 at 1:01
• I have put the -shell-escape command for the build of pdflatex as you mentionned in your first post. My pdflatex command line is then written pdflatex -shell-escape -synctex=1 -interaction=nonstopmode %.tex. – Alexandre Willame Sep 30 '14 at 18:14

Every now and then I have the same problem when compiling certain files. Of course, I have forgotten every time how I solved it in the past. Then, I google and I am getting to this page. Next, I remember that I landed on this page for several times, but, unfortunately, the answers did'nt help me in the past for my kind of problem. To break that Groundhog Day circle, I write down this answer which may help myself (for the next circle) and hopefully other people. The bad news is that it works only (?) for MikTeX users.

pdflatex --enable-write18 --extra-mem-bot=10000000 --synctex=1 <filename>


You may replace 10000000 by another ridiculous high number.

As was commented by @coatless, you may have to add --extra-mem-top=10000000 for other document types than my test example. The MiKTeX manual contains the following explanations:

• --extra-mem-bot=n: Set the extra size (in memory words) for large data structures like boxes, glue, breakpoints, et al. Relevant only after the memory dump file has been read.

• --extra-mem-top=n: Set the extra size (in memory words) for chars, tokens, et al. Relevant only after the memory dump file has been read.

For illustration some example log entries from a test document:

Failing example without the extra memory:

21229 strings out of 493921
360228 string characters out of 3152094
3000000 words of memory out of 3000000
24030 multiletter control sequences out of 15000+200000
49729 words of font info for 45 fonts, out of 3000000 for 9000
841 hyphenation exceptions out of 8191


Working example with --extra-mem-bot=10000000:

23652 strings out of 493921
401787 string characters out of 3152094
10571134 words of memory out of 13000000
24308 multiletter control sequences out of 15000+200000
49729 words of font info for 45 fonts, out of 3000000 for 9000
841 hyphenation exceptions out of 8191


Working example with --extra-mem-bot=100000000:

23652 strings out of 493921
401787 string characters out of 3152094
100571134 words of memory out of 103000000
24308 multiletter control sequences out of 15000+200000
49729 words of font info for 45 fonts, out of 3000000 for 9000
841 hyphenation exceptions out of 8191


I guess that my example in truth needed 571134 words of memory (and the the rest is eaten up for fun).

• I had to use --extra-mem-top=10000000 instead of --extra-mem-bot=100000000 on MikTex x64 (Win 10) as the previous one didn't work well. – coatless Feb 16 '16 at 12:38
• Many thanks @Coatless, I had the same issue, only worked with --extra-mem-bot – kabdulla Sep 5 '16 at 6:50
• @Coatless Thanks. The --extra-mem-top solved it for me. – Jean-Paul Nov 1 '16 at 22:03
• Working solution for me as a MikTeX user. I wish I had come to it earlier. It would have spared me a lot of time spent at debugging attempts on a long document I'm developing. – Marcos Jul 21 '17 at 9:44
• Sorry for my stupid question, but where do I type this? I am running Windows 7, Miktex 2.9 and Texmaker 4.5. – MrYouMath Nov 24 '17 at 22:00

Due to AlexG's comment, the memory size has been a constant large value for recent versions of TeX Live. It seems you don't need to extend this.

In older TeX Live, you can modify /some/path/to/texlive/some/subpath/web2c/texmf.cnf, which can be found by typing on the terminal:

kpsewhich -a texmf.cnf


Then modify the memory size by including, e.g. :

main_memory = 3000000


(See comments in texmf.cnf file for more details.)

Then run the following command as root to recreate the format files:

fmtutil-sys --all

• @Edin: your correction is wrong. The file mentioned by Leo Liu is the one to modify, as it's not touched by any TeX Live update. – egreg May 4 '11 at 8:41
• Thanks @egrep. In general things like that should not be modified directly but pointed out in a comment. – Martin Scharrer May 4 '11 at 10:20
• The /some/path/to/texlive/2010/texmf/web2c/texmf.cnf is the official config file which will be overwritten in an update. It should not be modified. Instead the /some/path/to/texlive/2010/texmf.cnf should be used to change all settings which are different from the default. This is pointed out in the comments of the main web2c/texmf.cnf config file, which maybe is what Leo Lio meant in his last sentence. – Martin Scharrer May 4 '11 at 10:23
• You can also set higher values for extra_mem_bot and extra_mem_top, which will give you even more memory in total. Also the description is saying that the maximum value for main_memory is 7999999. – 3244611user Feb 6 '17 at 8:53
• @LeoLiu : The maximum value main_memory = 12435455(to be found by bisection) has been a constant for many TL releases now. I think it is worth noting in the answer. – AlexG Jun 16 '17 at 7:10

after trying all the options (changing texmf.cnf file, etc.) I found on the web, the only one that worked for me was to use lualatex. This is the simplest and more elegant way to do it. Lualatex is available in the Texlive distribution by default.

• see macosx-tex.576846.n2.nabble.com/Lua-td6030741.html for instructions on using lualatex on a mac ::: note: in pdfLuaLatex.engine you may need to change pdflualatex -synctex=1 "$1" to lualatex -synctex=1 "$1" – C. Reed Jan 4 '13 at 13:19

It wasn't working for me either (MikTex on Win10 x64). I tried to change the pdflatex.ini file (see here point 4) but ended with the error after the dump:

Sorry, but "C:\Program Files\MiKTeX 2.9\miktex\bin\x64\miktex-pdftex.exe" did not succeed.


Therefore I did following: MikeTex Settings -> Formats, looked for pdflatex and clicked "Build". Again an error, but then I opened the pdflatex.ini, changed line for line the maximum value and looked up to which it still was able to succesful "Build".

Now it works with these values (8GB RAM):

main_memory=79999999
save_size=79999
extra_mem_bot=79999999
extra_mem_top=79999999
font_mem_size=799999
pool_size=7999999
buf_size=7999999
EnableWrite18=p
stack-size=200000
max-strings=79999999


Just to add to this if anyone still has this problem, I found a pretty simple way to fix it. I was getting this error:

TeX capacity exceeded, sorry [main memory size=5000000]


I went through a lot of guides to increase the main memory and nothing was working :/

But I read a few articles where they talked about save_size instead of main_memory.

I edited my texmf.cnf but not the one in the web2c folder, I changed the at in the ..../texlive/yyyy/texmf.cnf (since I'm using Windows my path was C:\texlive\2015\texmf.cnf). The file looked as follows:

% (Public domain.)
% This texmf.cnf file should contain only your personal changes from the
% original texmf.cnf (for example, as chosen in the installer).
%
% That is, if you need to make changes to texmf.cnf, put your custom
% settings in this file, which is .../texlive/YYYY/texmf.cnf, rather than
% the distributed file (which is .../texlive/YYYY/texmf-dist/web2c/texmf.cnf).
% And include *only* your changed values, not a copy of the whole thing!
%
OSFONTDIR = \$SystemRoot/fonts//


So I added the following two lines:

main_memory = 7999999
save_size  = 7999999


I then opened up command prompt and ran:

fmtutil-sys --all


And that was it :) I was able to build my stuff! I know that save_size wasn't mentioned at all in the error message but I found that adding that line fixed the issue :)!

By writing my document I also got this error. I found a nice workaround without using LuaLaTeX, changing any properties or making somehow a picture of your desired diagram. You can still using pdfLaTeX.

The following steps describe how you have to proceed:

# (1)

As usual, create your *.tex-file with matlab2tikz.

# (2)

Create a minimal working example (MWE) like the one. The example has some additional packages with the standalone class too remove unneeded margin:

\documentclass[preview]{standalone}
%I don't know, why I have to include the preview as an optional argument. Without I got an error.
\usepackage{graphicx}
\usepackage{pgfplots}
\pgfplotsset{compat=1.16}
\usepackage{siunitx}

\begin{document}

\begin{figure}[h]
\end{figure}

\end{document}


# (3)

With step (2) you can now include the generated *.pdf-file in your "normal" document:

...
\begin{figure}[h]
\includegraphics{< your generated *.pdf-file from step (2) >}
\caption[short text]{longer text}
\label{fig:figure1}
\end{figure}
...


As you can see the advantages of this methode is that you can also include captions and labels.