Does a killer nic card actualy do antthing?

I'm not sure what a "killer NIC" would be but any card that is atleast 10/100 will give you speeds up to 100 MBPs provided you have 10/100 on both ends of the cable which is more than plenty for internet use (most ISP speeds arent higher than 12Mbps) if you are transfering files between networked computers then you will see a speed difference between a 10/100 and a 10/100/1000 NIC but otherwise they are equals as far as internet goes