# Do MathJax macros have an influence on performance?

Consider the following three options when using MathJax:

1. normal MathJax

$$\mathbb{R}$$


2. Macro definition with MathJax

$$\def \R {\mathbb{R}}$$


3. Macro definition with script

<script>
MathJax.config.tex['macros'] = {
R: '{\\mathbb {R}}',
};
MathJax.startup.getComponents();
</script>


Is there a difference in efficiency for displaying cards between these options?

The macros can get more complex of course, this is just a simple example. Sometimes I use Anki on an old tablet, there I notice a slight delay with cards that use a lot of MathJax (option 1). But mostly I like to understand the difference between these options.

Also do the macros in the card template have any influence on the performance of cards that don’t use MathJax?