I had to do some research recently on data transmission speeds in computer networks and peripherals. While it was no real surprise that none of network and connection systems I looked at were likely to match up to their claimed speeds in typical use, it's interesting to note that some were closer than others.

All the 'actual speed' data below is open to question as it has been compiled from numerous sources across the web, some of which may not be authoritative. So use these figures with caution.

Network/Connection Headline
Speed Mbps
Actual
Speed Mbps
Actual
MBytes/sec

Wired networks

     

Ethernet 100 base T 'Fast Ethernet'

100 90 10.7
Ethernet 1000 base T 'Gigabit Ethernet' 1000 600 71.5
Wifi       
802.11b 'Wireless b' 11 5.5 0.7
802.11g 'Wireless g' 54 20 2.4
802.11n 'Wireless n' 72 40 4.8
802.11n with channel bonding 144? 90 10.7
USB       
USB 1.1 'Full-speed USB' 12 8? 1.0
USB 2.0 'Hi-speed USB' 480 320 38.1
Firewire      
Firewire 400 400 320 38.1
Firewire 800 800 640 76.3
Powerline networks       
Homeplug 1.0 14 5 0.6
Homeplug Turbo 85 10 1.2
Homeplug AV 200 40 4.8
Homeplug Mediaxtream 1000 90 10.7