ethtool

// man page of ethtool
$ ethtool -h

// Check statistic registers of network card
$ ethtool -S eth0

// See most of the registers of network card in interface eth0
$ ethtool -d eth0

// See the driver information
$ ethtool -i eth0

NIC: Intel e1000

more info:
http://www.globax.info/mediawiki/index.php/Intel_Gigabit_Performance