List of Intel NICs

List of Intel Network Controller

http://www.intel.com/content/www/us/en/ethernet-controllers/ethernet-controllers.html

Intel® 82574 Gigabit Ethernet Controller

Intel® 82541 Gigabit Ethernet Controller

Intel® 82540 Gigabit Ethernet Controller

e1000 network card info

http://developer.intel.com/products/ethernet/resource.htm?s1=all&s2=82541PI&s3=Datasheet#s1=Gigabit%20Ethernet&s2=all&s3=all

e1000 network card model:
82540EM
82541PI
......



Small difference between 82540EM and 82541PI




1. The default internal buffer size is different

82540EM : 16KB

82541PI: 24 KB




2. 82540EM can configure MSI control register at PCI configuration space, but 82541PI is a read only register

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

Change MTU setings for NIC interface in order to transfer Jumbo frames

mtu-value

Specifies the maximum transmission unit (MTU) or packet size that the vNIC accepts. Valid MTU values are 1500 to 9000 bytes; the default is 1500.

For CentOS:
$ vim /etc/sysconfig/network-scripts/ifcfg-eth0 

Add settings,
MTU="9000"

$ service network restart

it also could use command:
$ sudo ifocnfig eth1 mtu 16110


For Ubuntu
$ sudo ifconfig eth1 mtu 9000 up




Note: 
Regular network card MTU is from 1500 to 9000 bytes
Some powerful network card may support 16K packet size, which has max MTU 16110
This link talks about Intel Gigabytes NIC support 16K
http://communities.intel.com/thread/13247?wapkw=(mtu)

jumbo frames are Ethernet frames with more than 1500 bytes of payload.
1500 bytes doesn't include the Ethernet header
So the default MTU 1500 is the size of Ethernet frame payload


More info about Jumbo frames:
http://en.wikipedia.org/wiki/Jumbo_frame



more info about changing MTU:
http://www.cyberciti.biz/faq/centos-rhel-redhat-fedora-debian-linux-mtu-size/