This is a list of interface bit rates, a measure of information transfer rate, or digital bandwidth capacity, at which digital interfaces in a computer or network can communicate over various kinds of buses and channels. The distinction can be arbitrary between a computer bus, often closer in space, and larger telecommunications networks.
Many device interfaces or protocols (e.g., SATA, USB, SAS, PCIe) are used both inside many-device boxes, such as a PC, and one-device boxes, such as a hard drive enclosure. Accordingly, this page lists both the internal ribbon and external communications cable standards together in one sortable table.
Factors limiting actual performance, criteria for real decisions Most of the listed rates are theoretical maximum throughput measures; in practice, the actual effective throughput is almost inevitably lower in proportion to the load from other devices (network/bus contention), physical or temporal distances, and other overhead in data link layer protocols etc. The maximum goodput (for example, the file transfer rate) may be even lower due to higher layer protocol overhead and data packet retransmissions caused by line noise or interference such as crosstalk, or lost packets in congested intermediate network nodes. All protocols lose something, and the more robust ones that deal resiliently with very many failure situations tend to lose more maximum throughput to get higher total long-term rates.
Device interfaces where one bus transfers data via another will be limited to the throughput of the slowest interface, at best. For instance, SATA revision 3.0 () controllers on one PCI Express 2.0 () channel will be limited to the rate and have to employ more channels to get around this problem. Early implementations of new protocols very often have this kind of problem. The physical phenomena on which the device relies (such as spinning platters in a hard drive) will also impose limits; for instance, no spinning platter shipping in 2009 saturates SATA revision 2.0 (), so moving from this interface to USB 3.0 at for one spinning drive will result in no increase in realized transfer rate.
Contention in a wireless or noisy spectrum, where the physical medium is entirely out of the control of those who specify the protocol, requires measures that also use up throughput. Wireless devices, BPL, and modems may produce a higher line rate or gross bit rate, due to error-correcting codes and other physical layer overhead. It is extremely common for throughput to be far less than half of theoretical maximum, though the more recent technologies (notably BPL) employ preemptive spectrum analysis to avoid this and so have much more potential to reach actual gigabit rates in practice than prior modems.
Another factor reducing throughput is deliberate policy decisions made by Internet service providers that are made for contractual, risk management, aggregation saturation, or marketing reasons. Examples are rate limiting, bandwidth throttling, and the assignment of IP addresses to groups. These practices tend to minimize the throughput available to every user, but maximize the number of users that can be supported on one backbone.
Furthermore, chips are often not available in order to implement the fastest rates. AMD, for instance, does not support the 32-bit HyperTransport interface on any CPU it has shipped as of the end of 2009. Additionally, WiMAX service providers in the US typically support only up to as of the end of 2009.
Choosing service providers or interfaces based on theoretical maxima is unwise, especially for commercial needs. A good example is large scale data centers, which should be more concerned with price per port to support the interface, wattage and heat considerations, and total cost of the solution. Because some protocols such as SCSI and Ethernet now operate many orders of magnitude faster than when originally deployed, scalability of the interface is one major factor, as it prevents costly shifts to technologies that are not backward compatible. Underscoring this is the fact that these shifts often happen involuntarily or by surprise, especially when a vendor abandons support for a proprietary system.
Conventions By convention, bus and network data rates are denoted either in bits per second, (), (), (), () or bytes per second, (), (), (), (). In general, parallel interfaces are quoted in and serial in . The more commonly used is shown below in bold type.
On devices like modems, bytes may be more than 8 bits long because they may be individually padded out with additional start and stop bits; the figures below will reflect this. Where channels use line codes (such as Ethernet, Serial ATA, and PCI Express), quoted rates are for the decoded signal.
The figures below are simplex data rates, which may conflict with the duplex rates vendors sometimes use in promotional materials. Where two values are listed, the first value is the downstream rate and the second value is the upstream rate.
The use of decimal prefixes is standard in data communications.
Bandwidths The figures below are grouped by network or bus type, then sorted within each group from lowest to highest bandwidth; gray shading indicates a lack of known implementations.
As stated above, all quoted bandwidths are for each direction. Therefore, for duplex interfaces (capable of simultaneous transmission both ways), the stated values are simplex (one way) speeds, rather than total upstream+downstream.
Historical Technology Maximum rate Rate excluding overhead Year Smoke signals Throughout historyMorse code (skilled operator)4 characters per second (cps) ()1844Normal human speechPrehistoric
Radio clock Time signal station to radio clock Technology Maximum rate Year IRIG and related ~0.125 1960
Teletypewriter (TTY) or telecommunications device for the deaf (TDD) Technology Maximum rate Year TTY (V.18) 6 TTY uses a Baudot code, not ASCII. This uses 5 bits per character instead of 8, plus one start and approx. 1.5 stop bits (7.5 total bits per character sent). 1994 TTY (V.18) 6.6 1994 NTSC Line 21 closed captioning ~100 1976
Modems (narrowband and broadband)
Narrowband (POTS: 4 kHz channel) Technology Rate Rate excluding overhead Year Teleprinter (50 baud) 404 operations per minute 1940x Modem 110 baud (Bell 101) (~10 cps) 1959 Modem 300 (300 baud; Bell 103 or V.21) (~30 cps) 1962 Modem 1200/75 (600 baud; V.23) (~120 cps) 1964(?) Modem 1200 (600 baud; Vadic VA3400, Bell 212A, or V.22) (~120 cps) 1976 Modem 1200 (Bell 202C, 202D) (~150 cps) 1976 Modem 2000 (Bell 201A) (~250 cps) 1962 Modem 2400 (Bell 201B) (~300 cps) ? Modem 2400 (600 baud; V.22bis) 1984 Modem 4800/75 (1600 baud; V.27ter) 1976 Modem 4800 (1600 baud, Bell 208A, 208B) ? Modem 9600 (2400 baud; V.32) 1984 Modem 14.4 (2400 baud; V.32bis) 1991 Modem 28.8 (3200 baud; V.34-1994) 1994 Modem 33.6 (3429 baud; V.34-1996/98) 1996 Modem 56k (8000/3429 baud; V.90) 1998 Modem 56k (8000/8000 baud; V.92) 2001 Modem data compression (variable; V.92/V.44) 2000 ISP-side text/image compression (variable) 1998 ISDN Basic Rate Interface (single/dual channel) 1986 IDSL (dual ISDN + data channels) 2000Adam.com.au
Broadband (hundreds of kHz to GHz wide) Technology Rate Rate excluding overhead Year ADSL (G.lite) 1998 HDSL ITU a.k.a. DS1 1998 MSDSL ? SDSL ? SHDSL ITU 2001 ADSL (G.dmt) ITU 1999 ADSL2 ITU 2002 ADSL2+ ITU 2003 DOCSIS 1.0DOCSIS 1.0 includes technology which first became available around 1995–1996, and has since become very widely deployed. DOCSIS 1.1 introduces some security improvements and quality of service (QoS). (cable modem) 1997 DOCSIS 2.0DOCSIS 2.0 specifications provide increased upstream throughput for symmetric services. (cable modem) 2002 VDSL ITU 2001 VDSL2 ITU 2006 Uni-DSL 2006 VDSL2 ITU Amendment 1 (11/15) 2015 BPON (G.983) (fiber optic service) 2005 EPON (802.3ah) (fiber optic service) 2008 DOCSIS 3.0DOCSIS 3.0 includes support for channel bonding and IPv6. (cable modem) 2006 G.fast ITU 2019 GPON (G.984) (fiber optic service) 2008 DOCSIS 3.1DOCSIS 3.1 is currently in development by the Cablelabs Consortium (cable modem) 2013 10G-PON (G.987) (fiber optic service) 2012 DOCSIS 4.0 (cable modem) 2017 XGS-PON (G.9807.1) (fiber optic service) 2016 NG-PON2 (G.989) (fiber optic service) 2015 HSP (G.9804) (fiber optic service) 2019
Mobile telephone interfaces Technology Download rate Upload rate Year GSM CSD (2G) HSCSD GPRS (2.5G) WiDEN CDMA2000 1×RTT EDGE (2.75G) (type 1 MS) 2002 UMTS 3G EDGE (type 2 MS) EDGE Evolution (type 1 MS) EDGE Evolution (type 2 MS) 1×EV-DO rev. 0 1×EV-DO rev. A LTE Cat 1 1×EV-DO rev. B HSPA (3.5G) 4×EV-DO Enhancements (2×2 MIMO) HSPA+ (2×2 MIMO) LTE Cat 2 15×EV-DO rev. B LTE Cat 3 UMB (2×2 MIMO) LTE Cat 4 LTE (2×2 MIMO) 2004 UMB (4×4 MIMO) EV-DO rev. C LTE Cat 5 LTE Cat 6 LTE Cat 7 LTE (4×4 MIMO) LTE Cat 13 LTE Cat 9 LTE Cat 10 LTE Cat 11 LTE Cat 12 LTE Cat 16 LTE Cat 18 LTE Cat 21 LTE Cat 20 LTE Cat 8 LTE Cat 14 5G NR ?
Wide area networks Technology Rate Year 56k line 1990 DS0 G.lite (a.k.a. ADSL Lite) DS1 / T1 (and ISDN Primary Rate Interface) 1990 E1 (and ISDN Primary Rate Interface) G.SHDSL SDSL LR-VDSL2 (4 to 5 km [long-]range) (symmetry optional) T2 ADSL E2 ADSL2 Satellite Internet ADSL2+ E3 DOCSIS 1.0 (cable modem) 1997 DOCSIS 2.0 (cable modem) 2002 DS3 / T3 ('45 Meg') STS-1 / OC-1 / STM-0 VDSL (symmetry optional) OC-3 / STM-1 VDSL2 (symmetry optional) T4 T5 OC-9 OC-12 / STM-4 OC-18 DOCSIS 3.0 (cable modem) 2006 OC-24 OC-36 OC-48 / STM-16 OC-96 OC-192 / STM-64 10 Gigabit Ethernet WAN PHY DOCSIS 3.1 (cable modem) 2013 DOCSIS 4.0 (cable modem) 2017 OC-256 OC-768 / STM-256 OC-1536 / STM-512 OC-3072 / STM-1024
Local area networks