I just checked and I can confirm SS of 1/8000th with no curtain showing on both my Einsteins and Alienbees. That's pretty awesome.
Great thanks, did you have to use full power, and is that with the 1D4?
Thats pretty impressive though as the Einsteins have a short flash duration. Generally the slower they are the better. Thats why its usually best at full or lowest power (wherever your lights have the longest duration).