In a recent push for code clarity, the X.org folks decided that they will no longer support XAA acceleration (2D). It was supposed to be replaced by EXA. However, it turns that EXA implementation in many of their drivers for legacy video adapters (like SiS) is broken to a point of crashing the whole X server.
Fedora 18 comes with X.org version 1.13. Since there is no such release on the X.org site, it is likely that Fedora guys have taken some of the 1.12.9x development releases and shipped it as ‘1.13’. (Not their first, actually – remember gcc-2.96 back in RedHat times?)
The combination of the above two, however, leads to the fact that you cannot even install F18 on a system with a legacy card like SiS – and if you do, however, your only bet is unaccelerated X. The only way to get the SiS driver working is to enable ‘NoAccel’ in xorg.conf – which means significantly slower desktop and no Xv, i.e. all video playback goes through X11, making it slower and of poorer quality.
While I don’t have the knowledge to fix EXA in the SiS driver, with some efforts it is still possible to get back your XAA acceleration: Continue reading