## Changing TEXMF run-time parameters

You can control a number of run-time parameters (in particular, array sizes) on the command-line or in a configuration file.

Some of the more interesting paramaters:

main_memory

  Total words of memory available, for TeX, METAFONT, and MetaPost.

extra_mem_bot

  Extra space for large TeX data structures: boxes, glue, breakpoints, et al.

font_mem_size

  Words of font info available for TeX.

See Chapter 10, Run-Time Defaults, for a complete list of the TEXMF run-time parameters.

Here is a typical example of a configuration file:

    main_memory=2000000
    extra_mem_bot=2000000
    font_mem_size=2000000

The name of the configuration file is that of the engine (e.g., miktex-pdftex) or format (e.g, miktex-pdflatex). You use the `--edit-config-file` option of initexmf to edit the configuration file, e.g.:

    > initexmf --edit-config-file=pdflatex

    >