Wireshark · Ethereal-users: [Ethereal-users] high percentage of dropped frames in sniffing output

[John Que <qwejohn@xxxxxxxxx>]

Hello, 
  I am testing a heavy network server.
  The machine I am testing on is a strong one - 2 Xeon Processors (3.0 Ghz).
Now, I am using one Network Card.
I am trying to sniff from a command line to a file with

tethereal -f "host 10.0.0.1" -w "myOutput.txt"
I see that
from 612751
71442 packets dropped

this is about 11.6 % packets dropped !

My question is: 
is there a way to lower (or disable at all) the number of packets dropped? 
Is there some paramtere of the NIC upon which this parameter is dependent?

Regards,
John