[luatex] Performace comparison

[Andreas Scherer]

Dear all,

While working on next year's 'knuth-pdf' package 
(https://ctan.org/pkg/knuth-pdf) I have noticed that LuaTeX is the one 
PDF engine that revs up the fan of my laptop more than the others.

Running 'time makeall' (see 
https://mirrors.ctan.org/web/pwebmac/makeall) gives the following 
results (second run each):

$ time makeall -npt xetex
real    1m2,738s
user    1m7,745s
sys     0m8,641s
[$ wc -c *.pdf -> 30355436 total]

$ time makeall -npt pdftex
real    0m53,242s
user    0m53,042s
sys     0m2,140s
[$ wc -c *.pdf -> 40045111 total]

$ time makeall -npt luatex
real    1m15,286s
user    1m13,728s
sys     0m3,615s
[$ wc -c *.pdf -> 44176632 total]

Just an observation.

Best,
Andreas