How fast do you shift with manual transmissions?

How many seconds does a gear shift take?

I ve seen less than 0,5 seconds on 6 speed transmissions.

 

When you say shift, I take that to mean put in the cluch, shift to the desired gear, and let the clutch back out. A good driver can perform those three tasks in 0.2 sec or a little less.
If you count the time for the turbos to respool, you are looking at 0.4-0.5s total lost time in the shift...