Very bad SMB write speed

Troubleshooting
1

Hello

Since i updated to 3.9.2-19 from 3.9.1 I have very bad SMB write speeds:
image
It sometimes stalls completely.
Read speed is good and stable like before. Writespeeds on NFS are also fine:

image
image1027×60 11.1 KB

I do not use any custom config and everything was fine before the update.

2

I tried to use the following custom options:

write cache size = 2097152
use sendfile = yes
getwd cache = true
min receivefile size = 16384
socket options = IPTOS_LOWDELAY TCP_NODELAY SO_RCVBUF=65536 SO_SNDBUF=65536

But they didn’t change anything. Client is Windows 10 Version 10.0.14393.