Quote Originally Posted by Steph View Post
It seems there are conflicting info on that. I read 1/8000 elsewhere (either CR or DPR). I don't know for the X-sync.
As Darth Vader said, "There is no conflict." Canon's specs have the answer:

Shutter Speeds
1/4000 to 30 sec., X-sync at 1/180 sec. (Total shutter speed range. Available range varies by shooting mode.)