Name	Speed	Units	Can Duplex?	Notes
v.22	1200	bps	no	
v.22bis	2400	bps	no	first modem I owned  ;-)
v.32	9600	bps	no	
v.32bis	14.4	Kbps	no	
v.90	56	Kbps	no	current modems
DS0	64	Kbps		Digital Signal Designator 0, a base unit in the <a href="http://whatis.techtarget.com/definition/0,,sid9_gci212004,00.html">digital signal X</a> system
CD-ROM	1.2288	Mbps	no	a single-speed or "1x" CD-ROM drive
DSL/Cable	1.5	Mbps	no	just here for rough comparison; here's a <a href="http://119a.www7.50megs.com/summary.htm">DSL speed chart</a>
DS1/T1	1.544	Mbps	yes	24 voice channels at 64 Kbps; <a href="http://www.firstconnect.net/services/t_install.shtml">more info.</a> -- (1.544Mbit = 193-bit frames transmitted 8000 times per second)
E1	2.048	Mbps	yes	32 channels, European standard
Ethernet	10	Mbps	yes	
802.11b "Wi-Fi"	11	Mbps	no	effective speeds are much lower
DVD-ROM	11.08	Mbps	no	single-speed DVD-ROM transfer rate; roughly equivalent to a CD at 9x; <a href="http://www.dvddemystified.com/dvdfaq.html#4.2">spin rate is roughly 3x faster than a CD</a>
USB 1.x	12	Mbps	no	
32x CD-ROM	39.3216	Mbps	no	
SCSI-1	40	Mbps	no	the original, 8-bit <a href="http://www.scsita.org/terms/scsiterms.html">SCSI</a>
DS3/T3	44.736	Mbps		672 voice channels
OC-1/STM0	51.84	Mbps		base <a href="http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci212685,00.html">Optical Carrier</a> rate for the SONET system; Synchronous Transfer Mode (STM) is the Euro standard
802.11a/802.11g	54	Mbps	no	effective speeds are much lower
Fast SCSI	80	Mbps	no	8-bit
Fast Ethernet	100	Mbps	yes	
"Super G"	108	Mbps	no	double-rate, non-standard wireless protocol
ISA bus	128	Mbps	no	the old <a href="http://computer.howstuffworks.com/pci2.htm">PC bus standard</a>
OC-3/STM1	155.52	Mbps		three OC-1s; might be known as an E4 in Europe
16x DVD-ROM	177.28	Mbps	no	equivalent to a CD at ~144x
EISA bus	256	Mbps	no	
ATA/33	256	Mbps	no	ATA/ATAPI 4, Ultra DMA Mode 2 (not the original or slowest), <a href="http://www.pcguide.com/ref/hdd/if/ide/modes_PIO.htm">120ns cycle time, 2 bytes per cycle</a>
USB 2.x	480	Mbps	no	
IEEE-1394A Firewire	400	Mbps	no	
OC-12/STM4	622.08	Mbps		four OC-3s
Ultra2 Wide SCSI	640	Mbps	no	
IEEE-1394B Firewire	800	Mbps	no	
UltraATA/133	1	Gbps	no	
Gigabit Ethernet	1	Gbps	yes	
PCI bus, original	1.067	Gbps	no	original 32-bit, 33.3 MHz
SATA 150	1.2	Gbps	no	Serial ATA 150
OC-24	1.244	Gbps		
Ultra160 SCSI	1.280	Gbps	no	
OC-48/STM16	2.488	Gbps		
Ultra320 SCSI	2.560	Gbps	no	
PCI 64-bit, 66MHz	4.267	Gbps	no	
Ultra640 SCSI	5.120	Gbps	no	
PCI-X	8.333	Gbps	no	64-bit, 133.3 MHz
PC133 SDRAM	8.333	Gbps	no	
OC-192/STM64	9.953	Gbps	no	
Fast Gigabit Ethernet	10	Gbps	yes?	
OC-256	13.271	Gbps		
InfiniBand	30	Gbps		12-channel operation; each channel is 2.5 Gbps
OC-768	40	Gbps		
DDR533 dual channel	66.667	Gbps		DDR533 ram in a dual-channel configuration, 128-bit (2 x 64-bit), 533.3 MHz
HyperTransport 1.0	102.4	Gbps		
OC-3072	160	Gbps		
HyperTransport 2.0	179.2	Gbps		
HyperTransport 3.0	332.8	Gbps		
OC-768 with DWDM	6.4	Tbps		<a href="http://www.whnet.com/speed.html">"Enkido"</a>
glass fiber	150	Tbps		theoretical maximum capacity of one fiber as determined by physics. as with all theories, this one may already be proved wrong