[linux-audio-user] gnome-terminal performance

Lee Revell rlrevell at joe-job.com
Sat Jul 31 17:19:39 EDT 2004

On Sat, 2004-07-31 at 16:09, Florin Andrei wrote:
> On Sat, 2004-07-31 at 12:57, Chris Pickett wrote:
> > note that i don't like menubars or scrollbars or any of that crap, and 
> > aterm lets you get rid of them easily (scrollbar is shift+pgup/pgdn or 
> > shift+up/dn).
> Actually, gnome-terminal is good from a usability p.o.v. I like the way
> it has copy/paste keyb shortcuts, i actually use the Reset And Clear
> function (makes it easy to copy/paste huge swaths of text), etc.
> But, with JACK needing a smooth environment, gnome-terminal seems like a
> timed bomb. :-(

You *have* to use realtime scheduling if you want jackd to work. 
Period.  Otherwise, the system is doing exactly what you are telling it
to.  You have two processes, gnome-terminal and jackd, with the same
priority, so when both of them want to run, it's 50/50 who will get
scheduled.  It is *not* gnome-terminal's fault if scrolling text causes
XRUNs in jackd.

If jackd were running SCHED_FIFO aka realtime, and gnome-terminal as a
normal priority process, it would be a bug (priority inversion) if
gnome-terminal *ever* interfered with jackd's operation.


BTW it is trivial to demonstrate that gnome-terminal does in fact have
major performance problems.  Running 'top' in a maximized gnome-terminal
on a PII-450, the gnome-terminal process takes something like 20% of the
CPU.  Just to redraw a screen full of text once per second.  When a
program performs *that* much worse than another one for no good reason,
it is called a performance BUG.

I am surprised no one has mentioned the real reason gnome-terminal is
such a CPU hog - font anti-aliasing.  The GNOME people say this needs to
be hardware accelerated for decent performance, and that none of the
current video drivers do this.  However, Windows does the same thing on
the same machine WAY faster.  So either the Linux video drivers are
buggy, or Windows has a 100x faster way to anti-alias fonts.

I think the distros made the wrong choice in putting anti-aliasing into
their desktops before it was ready.  I am supposed to be impressed
because the desktop *finally* looks halfway decent compared to Windows,
except *way* slower?

I cannot believe the GNOME developers would respond to the original
complaint with 'hey, don't bug us about performance, we're still adding
FEATURES over here!  it's not really a problem, and if it is, you need a
faster machine'.  At least *pretend* to be interested in reining in the

Can't they understand that I do not want gnome-terminal on my 3Ghz
machine to be about as fast as xterm on a P133?  I bought a faster
machine because I want it to do basically the SAME stuff as the old one
but FASTER, and with a few more features!  Have you tried a
pre-anti-aliasing distro lately, like RH 7.3?  It SMOKES!  *Way*
snappier than today's equivalent.

Here is the main point they seem to miss:  If I upgrade from a circa
2000 machine (hardware and software) to a 2004, I expect the latter to
be significantly faster *AND* address the limitations of the old
software.  In no circumstances should it be slower, or even the same - I
just UPGRADED, remember?



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