Mono required by ubuntu-desktop

[Dan Kegel]

On 8/3/06, Scott James Remnant <scott at ubuntu.com> wrote:
> > Low-end PCs typically steal 64MB of that 256MB for video memory.
> > So the budget is really 192MB, not 256MB.
> > And ultra-low-end PCs have 128MB with 32MB stolen for video memory,
> > so their budget is really 96MB!
> >
> Not many PCs (at least not many I've ever encountered) steal the RAM for
> the video card, this tends to be a laptop trick (I'm willing to be
> corrected here, I've just not seen it in even the cheapest desktops).

Then you haven't looked carefully.  It is very common.
Dell's low end unit uses it:
http://compreviews.about.com/od/budgetdesk/gr/DimensionB110.htm
Heck, even Dell's low-end media computer uses it!  It's based on this chipset:
http://www.intel.com/products/chipsets/gma950/

> > > On an i386, the base OS uses around 32MB of memory and the
> > > desktop uses a further 80MB of memory ... so we're using about 112MB
> > > of memory before we've got any user applications loaded.
> >
> > On my dapper x86 system with 192MB or 512MB of RAM (booting
> > with either size gives similar values), all root processes total
> > 30MB of RSS (about what you quoted), but all user processes (not including
> > firefox; all I have open is bash) total 163MB.
>
> Ah, you've made the first mistake everyone does when talking about RAM
> usage.

Indeed, RSS looks unreliable.  (Do you happen to have a script that
displays a more reliable measure of memory size for each app?)

May as well measure what's really important: performance.
I took some measurements on a 1800MHz Athlon 64 machine running
32 bit Dapper, restricted to various amounts of system ram:

RAM   boot login abi ooo firefox
64MB  62 147 18 360? -
96MB  47 50  9  67 -
128MB 49 27 6 52 13
192MB 42 20 5 28 12
512MB 41 17 - - -

A reasonable criterion for acceptable performance is
"boot and log in in under 60 seconds".  Given this
criterion, even 192MB (the amount of free ram in
common 256MB systems with shared video ram)
is not quite enough, at least on my compaq r3000!
(And my measurement for login time may be an
underestimate; I counted it as done when the web browser
icon appeared in the upper menu bar, but I noticed
later that the icons on the right hand side appear several
seconds later.)

This is, as they say, a job for bootchart.   It would
be nice if we could make
"keep the boot + login time of Ubuntu
under a minute on systems booted with mem=192M"
a goal going forward.
- Dan