Re: CPU usage and barchecks

[James Harkins]

Antonio Gervasoni <agervasoni <at> gmail.com> writes:

> I've been using Lilypond for over a year and I've always noticed it requires
> a lot of CPU resources to engrave a score. This is especially noticeable
> when working on big orchestral scores. I use a Macbook Pro and one single
> engraving of an orchestral score, speeds up the fan and the left-hand corner
> of the machine gets very hot. This doesn't happen when I process a single
> instrument part; although, if I make changes and process the part several
> times in quick succession, the machine gets equally hot.

This is normal for any large and complex job of compiling from source code. The 
compiler is supposed to read the code and convert it to something else (another 
kind of code, or here, PDF) as fast as possible. Often that means maxing out at 
least one CPU core for as long as the job is running.

Another example: I've been using LaTeX beamer documents for presentations (by 
way of org-mode export, but that's not strictly relevant). These are shorter 
documents (20-30 "pages") and there's a lot less visual information on each 
page 
than there would be in a full orchestral score, but still, the CPU meter 
reports 
that one core is working full speed for 5 seconds or so.

I also see full CPU use for several minutes when I rebuild SuperCollider from 
source (especially after a header file changed, which forces all dependent 
files 
to be recompiled).

It's inherent in the write-compile-edit-recompile workflow. This architecture 
gives lilypond some distinct advantages in the marketplace, but it does have 
the 
disadvantage that even a small change requires redoing all of the typesetting 
work from scratch. I don't think anyone would say that this is not a 
disadvantage of lilypond -- but, for my uses at least, lilypond's advantages 
more than compensate.

Computers are supposed to be designed to handle intensive demands. That's why 
your fan spins up -- it's the hardware doing what it's supposed to do to keep 
everything working while the computer has a harder job to finish.

hjh