Small problem with NFS

[alaci]

I tested the NFS and Samba.

SAMBA stable but make high network traffic.

The NFS network traffic low but do not stable. Sometimes it does not start playing (unknown format error) or sometimes jump to the next film.

My mount info (cat /proc/mounts):

SAMBA:
//x.x.x.x/share /dtv/usb/smb/x.x.x.x/share cifs rw,unc=\\x.x.x.x\share,username=yyy,rsize=16384,wsize=32768 0 0

NFS:
x.x.x.x:/share /dtv/usb/nfs/x.x.x.x/share nfs rw,vers=3,rsize=524288,wsize=524288,soft,nolock,proto=tcp,timeo=70,retrans=3,sec=sys,addr=x.x.x.x 0 0

How do I set up the SAMBA rsize/wsize greater? Manual mount does not change it.

rsize 16384 -> 524288
wsize 32768 -> 524288

Sorry poor English!

Regards
alaci