[Bug 46119] Re: poor desktop performance on compiz

[Killercow]

His card is fast enough, the problem might be the memmory on the card,
it is shared with rest of the system, and thus is not a dedicated set of
ram-chips.

Because these chips are on the other side of the agp-bus, performance
might take a hit if the textures are really big. Are you using a large
(as in MB's) desktop wallpaper?

Try removing it, and just using an opaque background color. That might help a lot.
Offcourse testing with a speedier, card with onboard ram would also prove this.

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poor desktop performance on compiz
https://launchpad.net/bugs/46119