[Samba] Samba 4 is half as fast as Samba 3?!

[Oliver Lehmann]

Hi,

[global]
         max protocol = NT1

in seems to bring back more or less the performance I was used to
with Samba 3. NT1 was the default in Samba 3, while SMB3 seems to
be the default in Samba 4. I also tried

[global]
         aio read size = 1
         aio write size = 1
         use sendfile = true

But those made no big difference.