(In reply to comment #7)
> Yes that's the same corruption I have with the native backend. I suggest you
> to have a look at top: native isn't slow, but aftware a few minutes the X
> process starts eating the CPU ,that's the reason ;)

In my case, X doesn't normally use much cpu (~10-15%) (well, really depends on
your definition of 'much'), but there are moments (every 2-3 seconds) where it
peaks at ~45-60% which causes everything to lag for a moment (for example if I
move a window or even with glxgears)...

And btw, thanks for the vblank tip, it helped a little.