Firewire 400 is Standard 400Mbps Firewire 1394a. It supports speeds of up to 400Mbps depending on device capabilities. The connectors are of two types: 6-pin and 4-pin. The 4-pin is very small and is used for Laptops, Camcorders and small portable hard drives. 6-Pin is widely used on Desktop Pc's and Macs.