Re: Enabling blur in kwin slows down the desktop effects
If you compare KDE 4.5 RC1's blur with 4.5.0's blur, 4.5.0 is an order of magnitude faster. This isn't about the genius programming the blur, this is more about a new effect (4.2.0 blur was scrapped completely) that needs testing, testing and more testing. Also, the effect isn't optimized, we can see it blurring blurred regions all of the time, specially with the oxygen-transparent branch.
OTOH, KDE 4.6 is expected to upgrade the KWin compositing engine to OpenGL 2.0. Maybe we see something interesting going out from there.