Re: ps/tt fonts in gnome apps

[Havoc Pennington <hp redhat com>]

On Thu, 16 Sep 1999, Miles Lane wrote:
> Has a request for this functionality been made to the XFree86 people?

Presumably they know about the problem, I'm not sure it's easy for them to
solve. Fonts are a very complicated problem and the XFree people are
probably experts on graphics cards, not fonts.

> why is X such a memory hog?  It seems to me that

It isn't really. Note that the "X" process contains lots of resources
(pixmaps and windows, etc.) that actually belong to applications. So if
your X is using tons of RAM it's likely because you are running lots of
apps. If you run E or GTK with a pixmap theme you'll really chew up some
RAM - note that all those pixmaps are stored in X, not in the apps.

Now do the math; graphics are _big_. That's why video cards come with 4
and 8 and even more megs of RAM, even though they're displaying a single
screen (I guess the ones with a really large amount of RAM put more than a
single screen in it, but you get the idea.) Multiply the number of pixels
on your screen (say 1024x768) times the number of bytes per pixel (1 for
256 colors, 2 for 16 bpp, 3 for 24 bpp, 4 for 32 bpp). Now double it if
you use background pixmap, since you are storing the pixmap plus the final
screen. Now add any different background pixmap on other desktops. Now add
windows and theme pixmaps.

X's expose event model does allow it to "forget" concealed window regions,
which saves a lot of memory.

You might do a little bit better with a different window system design,
but it's physically impossible to do all that much better. You have to put
the pixels somewhere. There's just no way around it. The bulk of X's
memory usage is in storing those pixels, so there isn't much room to shave
resources.

Remember that X was designed something like 15 years ago, when hardware
was far inferior...

Havoc