[luatex] LuaTeX precompilation

[Herbert Voss]

Am 20.12.23 um 18:44 schrieb blumens at fi.muni.cz:
> Hans Hagen wrote:
>> On 12/20/2023 3:48 PM, Axel Kittenberger wrote:
>>> Sorry, but I have to disagree here, for me the performance
>>> differences were indeed a dealbreaker for me to push lualatex as a
>>> general purpose replacement in my department.
>> In documents of average complexity i normally get 30 page/second
>> performance. On more complex documents pdftex can be slower. I have a
>> 2017 laptop so more modern hardware will gove lower numbers
> I agree with Alex here. Performance is the only reason I haven't
> switched to lualatex for all my documents yet.
>
> For instance, I get the numbers
>
>     8 s  for pdflatex
>    12 s  for lualatex with the same TFM fonts
>    18 s  for lualatex using luaotfload and fontspec instead
>
> This was for a math heavy document of about 600 pages using large OTF fonts.

Using pdftex and luatex for a 500 pages TeX document (TL2023)

pdftex:
real    0m1.330s
user    0m1.272s
sys    0m0.050s

luatex
real    0m1.822s
user    0m1.715s
sys    0m0.077s


for LaTeX it is obvious that lualatex is much slower than pdflatex:
a lot of packages check for luatex and insert some luacode ...

Herbert


>
> This performance difference is very noticeable. 8 s compile times are
> fine, but having to wait 18 s interrupts my workflow.
>
> Note that I did not spend time to figure out what causes the slowdown.
> It might be harfbuzz, but it also might be fontspec, which wouldn't be
> luatex's fault.
>
> Achim