LinuxQuestions.org - lan speed to low for Gbit connection

Recently I established a share connection between an ubuntu 10.04 server and a windows 7 workstation.
The shared folder is on the win computer, and most traffic goes from server to workstation.
Both computers have Gbit nics and both have a lan connection to a Gbit router.
The speed of file transfers is disappointing, just 110Mbit. My internet connection has 120Mbit bandwidth and very often I reach 150Mbit.
I have tested my share connection with Iperf:

Code:

root@server:~# iperf -c 192.168.1.9 -w 2m

------------------------------------------------------------

Client connecting to 192.168.1.9, TCP port 5001

TCP window size:  256 KByte (WARNING: requested 2.00 MByte)

------------------------------------------------------------

[  3] local 192.168.1.3 port 33442 connected with 192.168.1.9 port 5001

[ ID] Interval      Transfer    Bandwidth

[  3]  0.0-10.0 sec  1013 MBytes    850 Mbits/sec





root@server:~# iperf -s

------------------------------------------------------------

Server listening on TCP port 5001

TCP window size: 85.3 KByte (default)

------------------------------------------------------------

[  4] local 192.168.1.3 port 5001 connected with 192.168.1.9 port 55775

[ ID] Interval      Transfer    Bandwidth

[  4]  0.0-10.0 sec  1.09 GBytes    933 Mbits/sec

In my humble opinion these test results look great, but question is what can be limiting my bandwidth.
The share connection uses samba cifs.
I am awfully inexperienced with network connections.