Gnome 2.4 and anti-aliased font slowness

thebard · n00b Joined: 11 Sep 2002 Posts: 15

Rescently I upgraded my work box to Gnome 2.4 (from 2.2) Everything runs fine and seems happy. Except one thing.

I have a 17" LCD and had AA fonts on (Subpixel smoothing). I noticed a small speed hit with it on with Gnome 2.2 but it wasnt all that bad. With 2.4 its horrid.

Basicly under heavy scrolling in Gnome terminal top is reporting 70-80% cpu useage for X. I'm using a Radeon 7500 with all the 7500 options on. The Xfree log is showing full hardware acceleration including DRM and DRI support.

I tried experimenting with the details section of the Font configuration panel. The HINTING option has no speed inpact. Basicly, its the Smoothing option. any smoothing (besides None) causes a huge speed hit. At none gnome terminal scolls all out and uses about 50% of the cpu (which in and of itself seems a bit high) and X uses about 20-30%. Turning any smoothing on causes X to rocket to 70-80% cpu use.

The box I'm running Gnome on isnt brand new, but its not a light weight either. 512 megs of ddr 2100, Athlon XP 1800. The whole box is compiled with:
CFLAGS="-O3 -march=athlon-xp -pipe -fomit-frame-pointer --fast-math -m3dnow "

So, anyone notice this?

Roguelazer · Posted: Tue Sep 30, 2003 8:06 pm Post subject:

What kind of video card do you have?
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thebard · n00b Joined: 11 Sep 2002 Posts: 15

As posted above a radeon 7500. Not the fastest card in the world, but I don't game at all on this work box. It seems to run the 3d screensavers fast enough though

thebard · n00b Joined: 11 Sep 2002 Posts: 15

Another thing I noticed: Minimizing the gnome-terminal does not speed it up at all. X is still using 70-80% of the cpu when scrolling (like doing a ls -alR /)

I guess this means that X is double buffering and rendering the AA fonts on a back buffer then bliting them over to the front buffer. While this is great and all for smoothness, Its still being done even when the window isn't visable. Kinda sloppy me thinks

thebard · n00b Joined: 11 Sep 2002 Posts: 15

And it gets better. If I create a new tab over a scrolling window, (in gnome-terminal) X load goes way down and the thing scrolls like a madman (hidden). Just like you would expect. But if i minimize the window, X load stays up.

So there is definately at least one bug here... minimizing isnt marking the winow/pane as hidden to X

Still doesnt help my AA problems though

aethyr · Veteran Joined: 06 Apr 2003 Posts: 1085 Location: NYC

Make sure that your terminal isn't transparent.

I think on some setups this gets turned on by default.

thebard · n00b Joined: 11 Sep 2002 Posts: 15

nope, not transparent.