samba - Apr 2017 - Speed tuning

I have a Rootserver-> V-Server -> vpn-> samba  connection. -1 
GBit/s-Port: Granted 200 MBit/s: MAX 1 GBit/s: ...


Using vpn direct I get the maximum speed of the local internet 
connection about 6MiB/s
Using samba the maximum speed is about 2,6 MiB/s for a single download 
and twice 2.2MiB/s for a double download

Upload is the same as my internet connection 1MiB/s
I increased the speed with changing some values in the smb.conf, but i 
am not able to set it to the maximum speed

...
socket options = TCP_NODELAY SO_RCVBUF=524288 SO_SNDBUF=524288 
SO_KEEPALIVE IPTOS_LOWDELAY
log level = 0
min receivefile size = 65536
use sendfile = true
aio read size = 65536
aio write size = 65536
write cache size = 2048000
read raw = yes
write raw = yes
getwd cache = yes
oplocks = yes
max xmit = 65536
dead time = 15
large readwrite = yes
...
How can I speedup the download?

Best Regards Knut

Am 21.04.2017 um 08:06 schrieb Knut Krüger via samba:

I Just realized the a windows 7 client is not working
with:
> ...
> socket options = TCP_NODELAY SO_RCVBUF=524288 SO_SNDBUF=524288
> SO_KEEPALIVE IPTOS_LOWDELAY
> log level = 0
> min receivefile size = 65536
> use sendfile = true
> aio read size = 65536
> aio write size = 65536
> write cache size = 2048000
> read raw = yes
> write raw = yes
> getwd cache = yes
> oplocks = yes
> max xmit = 65536
> dead time = 15
> large readwrite = yes
but with
min receivefile size = 2048
use sendfile = true
aio read size = 2048
aio write size = 2048
write cache size = 1024000
read raw = yes
write raw = yes
getwd cache = yes
oplocks = yes
max xmit = 32768
dead time = 15
large readwrite = yes


Both results in speed are similar

Regards Knut