(This question is not about writing benchmarks/profiling elisp code, for that, see this question.)

Do any benchmark suites exist for Emacs performance? I'm looking for something equivalent to the V8 interpreter team's standard benchmark or the pypy team's benchmark suite.

I'd like to be able to answer questions like 'is Emacs 24.4 faster than 24.3?'.

Are there any existing benchmark suites?

  • 2
    I think the people talking about Guile VM should be able to give us some pointers, as the advantage always coming back is how faster it is vs Elisp.
    – Nsukami _
    Commented Oct 3, 2014 at 18:39
  • Speed is a factor in using Guile VM, but a proper FFI and thread support are also on the list and arguable more important.
    – dgtized
    Commented Oct 10, 2014 at 21:26

1 Answer 1


I don't know of any good performance benchmark for Emacs, sadly. Part of the reason is that it depends on what you want to measure (redisplay performance? I/O performance? ...).

Regarding Elisp performance in particular, the lack of benchmark is a symptom of the relative lack of work on improving its performance. FWIW, when working on the implementation of lexical-binding, I did use a benchmark to try and make sure that this new feature did not come at the cost of lower performance.

This benchmark I used is:

rm **/*.elc lisp/loaddefs.el; make -jN

running it from within Emacs's source causes all Elisp files to be recompiled, and the byte-compiler is one of the relatively few pieces of Elisp which run for long periods of time and can easily be run in batch mode.

The downside is that this is a moving target, since the time taken depends on the version of the byte-compiler you're using as well as on the version of Emacs you're compiling.

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