Hello,
I reported this problem a while back, but I don't think people believed me !! :)
Any way it still happens with XFree86 4.0 and XFree86-3.3.6-14mdk
Start something like morph 3D from Mesa-demos. It will run at top speed for
about 10 seconds, then it will slow to a crawl.
Now move the mouse around, anywhere on the screen will do. Morph 3D will run at
full speed again as long as the mouse is moving. Stop moving the mouse at it
will slow to a crawl again !
It appears that all Mesa 3D demos, 3D screensavers etc. all slow to a crawl
after about 10 seconds
Owen