Re: XVideo performance degradation with 8178
For the record, I've seen the same sync-to-vblank X hangup bug w/ my 6200 @ 1080i. It definitely was present in 7676 (and still in 8178).
When sync-to-vblank is disabled, however, I haven't seen any significant performance differences playing back HD streams. Just some nasty tearing artifacts I'm assuming are due to the fact that the rendering isn't properly synced (also in 7676).