[Samba] 3.6.8 and 4.1.3 throughput compassion

[sp bglr]

Hi All,

My doubts are for Samba4.1 performance related enhancements.Following is
the comparison result samba 3.6.8 + samba4.1.3.

Following number is robocopy 2 flow result.

3.6.8
Read/Write (speed MB/sec) :  210/*202*

4.1
Read/Write: (speed MB/sec) : 220/*192*

In case of read am getting better throughput for samba 4.1 but write always
less.

How can i improve the write throughput?

Am not looking to change any registry settings .(
http://technet.microsoft.com/en-us/library/ff625695%28v=WS.10%29.aspx).

Following tuning i already tried.

http://h3x.no/2011/07/09/tuning-ubuntu-mdadm-raid56
https://erikugel.wordpress.com/tag/mdadm/

Any idea or suggestion are most welcome.Thanks in advance.

Regards,
Bglr