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Old 04-01-06, 08:02 AM   #49
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Join Date: Feb 2004
Posts: 585
Default Re: Slow AA text rendering in KDE

I wrote a small QT application which does not more than painting strings to screen, its my first QT app so don't expect too much.

It prooves my estimates that the GF6600 system is about 4x slower than my old GF488Go powerd laptop.
Therefor this is NOT an KDE problem, nor related to badly written applications!

This benchmark uses the default font which is on all of my three systems Sans with size 10. If you plan to run it yourself make sure the window is completly ereased (minimize and show it to get this result). not-complete repaints will show with shorter times.

You can find it here: (precompiled for fedora core4)

Here are the results of my system:
AMD Duron 800 / VIA KT133 / FX5200 / FC4 from-cd:
RGB Subpixel AA: 53s
Greyscale Subpixel AA: 4s
No AA: 3s

Pentium4 Northwood 2.6ghz / SiS chipset / GF488Go / FC4 updated to latest
RGB Subpixel AA: 32s
Greyscale Subpixel AA: 2s
No AA: 1s

AMD Sempron 3100+ / nForce4 / GF6600 PCIe / FC4 from-cd
RGB Subpixel AA: 116s
Greyscale Subpixel AA: 1s
No AA: 1s

lg Clemens

PS: Note that KDE seems to leave subpixel-AA enabled if you had it enabled but just disable the subpixel-checkbox in the subpixel-dialog (bug?).
Thats why I first believed that non-subpixel-AA is slow too. If you select subpixel-greyscale instead kde disables rgb-subpixel and its as fast as non-subpixel-AA.
Edit: This only affects KDE-3.4, KDE-3.5 sets subpixel-aa right if you disable the checkbox.

Last edited by Linuxhippy; 04-01-06 at 12:37 PM.
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