Performance change from X in Fedora Core 4 to Fedora Core 5

Roo oscosc at
Sun Jul 9 07:15:53 PDT 2006

On Sun, 09 Jul 2006 22:21:11 +0900, Carsten Haitzler wrote:

> sorry to say that chances are is its the cairo move - cairo using
> xrender and xrender basically being horrible in terms of speed on all
> but the barest few chipsets if you are lucky. this is not something new
> - it has been hashed and rehashed. the problem is basically xrender is
> falling back to software rendering as there is no hardware accel - and
> software xrender is like deciding to go from los angeles to seattle by
> relying on continental drift. it has improved - but it is still bad -
> and the only major savior is a lot of extremely funky caching code to
> shadow drawables in system ram and smartly transfer only the updated
> sections TO the card as writes to avoid reads, or to move al drawables
> to system ram (try shadowfb if its available for mga drivers - haven't
> used them in years so i can't say),

If you mean:

Option     "ShadowFB"                  "true"

in xorg.conf. I've tried that, and it's even slower.

> change gfx card (ati r200 for example has render accel (albeit a little
> buggy)),

See, this is what I don't understand. I thought the Matrox cards had
really good render extension acceleration. That's why I asked if version 7
has gone backwards and broken it... but I'm only an interested user not a
coder, so all I see is a system that just keeps getting slower and a
PC/gfx card that is 100% free software being dropped in favour of newer
cards with closed drivers.

> downgrade gtk back to before cairo,

Not an option, I'm afraid. The GNOME developers decided to depend on the
version of GTK that dropped everything else but Cairo. Nice of them to
shaft everyone with older cards... so much for the performance

>oe start helping to add acceleration to all the x drivers for xrender.

I'd love to, but I wouldn't even know where to start. It makes for
depressing reading though.

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