Hi all:

I'm trying to play a high bit-rate 1080p film(about 30Mbps) through cifs mount with wireless network. But the max bandwidth can only reach 20Mbps.
I did some efforts to trace the issue as below:
 
1). Mount and play the file through nfs instead of cifs with wireless network.
    The bandwidth can reach 30Mbps without problems. Then I try to copy a file
    from cifs it even reach 70~80Mbps with nfs. But it holds on 20~25Mbps with
    cifs.

2). Mount and play the file through cifs with wired network.
    The bandwidth can reach 30Mbps. Copy action works well too.

3). Using iperf to detect the max bandwidth of wireless network. 
    It shows at least 40~50Mpbs.

4). All films with bit-rate below 20Mbps play smooth through cifs with wireless network.

5). And I have tested more than one wireless AP and wireless dongle. They all lead to the same result.

6). I also modified the CIFSMazBufSize, cifs_min_rcv, cifs_min_small, cifs_max_pending values. That doesn't have great improvement.

Environment information:
-Wireless:802.11n Bit Rate:150 Mb/s
-Server:a) Linux-2.6.27.10 x86 Samba-3.0.23c-2
        b) Windows Vista 
-Client:  Linux-2.6.23.9 x86 cifs-1.50

I wonder if the problem comes from cifs file system?
Are there any suggestions to tune the performance? 

Thx and best regards,
Terry