List of device bandwidths
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This is a list of device bandwidths: the channel capacity (or, more informally, bandwidth) of some computer devices employing methods of data transport is listed by bit/s, kilobit/s (kbit/s), megabit/s (Mbit/s), or gigabit/s (Gbit/s) as appropriate and also MB/s or megabytes per second. They are listed in order from lowest bandwidth to highest.
Whether to use bit/s or byte/s (B/s) is a matter of debate. The most commonly cited measurement is bolded. In general, parallel interfaces are quoted in byte/s (B/s), serial in bit/s.
Many of these figures are theoretical maxima, and various real-world considerations will generally keep the actual effective throughput much lower. See Measuring network throughput. The actual throughput achievable on Ethernet networks, for example (especially when heavily loaded), is a subject of hot debate.
Note: In telecommunications, 1 kbit/s = 1 000 bit/s, NOT 1 024 bit/s. Thus, all values below use metric prefixes. 1
| CONNECTION | BITS | BYTES |
|---|---|---|
[edit] TTY/Teleprinter or Telecommunications device for the deaf(note: TTY uses Baudot code, not ASCII. This uses 5 bits per character instead of 8, and one start and 1.5 stop bits.) |
||
| TTY (V.18) | 45 bit/s | 6 cps |
| TTY (V.18) | 50 bit/s | 6.71 cps |
[edit] Modems(note: serial, 1 start bit, 8 data bits, 1 stop bit: therefore 10 bits needed to transmit each byte. The exception is 110 baud which uses 2 stop bits or 11 bits per byte.) |
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| Modem 110 baud | 110 bit/s | 10 B/s |
| Modem 300 baud (V.21) | 300 bit/s | 30 B/s |
| Modem Bell 103 (Bell 103) | 300 bit/s | 30 B/s |
| Modem 1200 (V.22) | 1.2 kbit/s | 120 B/s |
| Modem Bell 212A (Bell 212A) | 1.2 kbit/s | 120 B/s |
| Modem 2400 (V.22bis) | 2.4 kbit/s | 240 B/s |
| Modem 9600 (V.32) | 9.6 kbit/s | 960 B/s |
| Modem 14.4k (V.32bis) | 14.4 kbit/s | 1,440 B/s |
| Modem 19.2k (V.32terbo) | 19.2 kbit/s | 1,920 B/s |
| Modem 28.8k (V.34) | 28.8 kbit/s | 2,880 B/s |
| Modem 33.6k (V.34plus/V.34bis) | 33.6 kbit/s | 3,360 B/s |
| Modem 56k* (V.90) (downstream) | 56.0 kbit/s | 5.6 kB/s |
| Modem 56k* (V.90) (upstream) | 33.6 kbit/s | 3.36 kB/s |
| Modem 56k* (V.92) (downstream) | 56.0 kbit/s | 5.6 kB/s |
| Modem 56k* (V.92) (upstream) | 48.0 kbit/s | 4.8 kB/s |
* See Notes section below for 56k caveats
[edit] ISDN |
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| ISDN Basic rate (BRI) signalling channel (D-channel) | 16.0 kbit/s | 2 kB/s |
| Single ISDN channel (B-channel) -(both Primary and Basic rate) |
64.0 kbit/s | 8 kB/s |
| Primary rate ISDN signalling channel (D-channel) | 64.0 kbit/s | 8 kB/s |
[edit] Computer buses |
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| ISA 8-Bit/4.77 MHz | 38.18 Mbit/s | 4.77 MB/s |
| ISA 16-Bit/8.33 MHz | 133.33 Mbit/s | 16.67 MB/s |
| HP-Precision Bus | 23 MB/s | |
| EISA 8-16-32bits/8.33 MHz | 320 Mbit/s | 32 MB/s |
| VME64 32-64bits | 400 Mbit/s | 40 MB/s |
| NuBus 10MHz | 400 Mbit/s | 40 MB/s |
| MCA 16-32bits/10 MHz | 660 Mbit/s | 66 MB/s |
| NuBus90 20MHz | 800 Mbit/s | 80 MB/s |
| Sbus 32-bit/25 MHz | 800 Mbit/s | 100 MB/s |
| PCI 32-bit/33 MHz | 1066.66 Mbit/s | 133.33 MB/s |
| HP GSC-1X | 142 MB/s | |
| Sbus 64-bit/25 MHz | 1600 Mbit/s | 200 MB/s |
| PCI Express (x1 link)† | 2500 Mbit/s | 250 MB/s |
| HP GSC-2X | 256 MB/s | |
| PCI 64-bit/33 MHz | 2133.33 Mbit/s | 266.66 MB/s |
| PCI 32-bit/66 MHz | 2133.33 Mbit/s | 266.66 MB/s |
| AGP 1x | 2133.33 Mbit/s | 266.66 MB/s |
| AGP 2x | 4266.66 Mbit/s | 533.33 MB/s |
| PCI 64-bit/66 MHz | 4266.66 Mbit/s | 533.33 MB/s |
| PCI-X DDR 16-bit | 4266.66 Mbit/s | 533.33 MB/s |
| PCI Express (x4 link)† | 10000 Mbit/s | 1000 MB/s |
| AGP 4x | 8533.33 Mbit/s | 1066.66 MB/s |
| PCI-X 133 | 8533.33 Mbit/s | 1066.66 MB/s |
| PCI-X QDR 16-bit | 8533.33 Mbit/s | 1066.66 MB/s |
| InfiniBand single 4X | 10.00 Gbit/s | 1.25 GB/s |
| AGP 8x | 17.066 Gbit/s | 2.133 GB/s |
| PCI-X DDR | 17.066 Gbit/s | 2.133 GB/s |
| PCI Express (x8 link)† | 20 Gbit/s | 2 GB/s |
| PCI Express (x16 link)† | 40 Gbit/s | 4 GB/s |
| PCI-X QDR | 34.133 Gbit/s | 4.266 GB/s |
| HyperTransport (800 MHz, 16-pair) | 51.2 Gbit/s | 6.4 GB/s |
| HyperTransport (1 GHz, 16-pair) | 64 Gbit/s | 8 GB/s |
| PCI Express 2.0 (x32 link)† | 80 Gbit/s | 8 GB/s |
| HyperTransport (2.6 GHz, 32-pair) | 166.4 Gbit/s | 20.8 GB/s |
† Note that PCI Express lanes use an 8B/10B encoding scheme
[edit] Computer buses (storage) |
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| SCSI 1 | 12.0 Mbit/s | 1.5 MB/s |
| PIO Mode 0 | 26.4 Mbit/s | 3.3MB/s |
| PIO Mode 1 | 41.6 Mbit/s | 5.2MB/s |
| PIO Mode 2 | 66.4 Mbit/s | 8.3MB/s |
| Fast SCSI 2 | 80 Mbit/s | 10 MB/s |
| PIO Mode 3 | 88.8 Mbit/s | 11.1MB/s |
| PIO Mode 4 | 133.3 Mbit/s | 16.7MB/s |
| Fast Wide SCSI 2 | 160 Mbit/s | 20 MB/s |
| Ultra DMA ATA 33 | 264 Mbit/s | 33 MB/s |
| Ultra Wide SCSI 40 | 320 Mbit/s | 40 MB/s |
| Ultra DMA ATA 66 | 528 Mbit/s | 66 MB/s |
| Ultra-2 SCSI 80 | 640 Mbit/s | 80 MB/s |
| Serial Storage Architecture SSA | 640 Mbit/s | 80 MB/s |
| Ultra DMA ATA 100 | 800 Mbit/s | 100 MB/s |
| Fibre Channel 1GFC (1.0625 GHz) | 850 Mbit/s | 106.25 MB/s |
| Ultra DMA ATA 133 | 1.064 Gbit/s | 133 MB/s |
| Serial ATA (SATA-150) | 1.2 Gbit/s | 150 MB/s |
| Ultra-3 SCSI 160 | 1.28 Gbit/s | 160 MB/s |
| Fibre Channel 2GFC (2.1250 GHz) | 1.7 Gbit/s | 212.50 MB/s |
| Serial ATA (SATA-300) | 2.4 Gbit/s | 300 MB/s |
| Serial Attached SCSI | 3.0 Gbit/s | 300 MB/s |
| Ultra-320 SCSI | 2.56 Gbit/s | 320 MB/s |
| Fibre Channel 4GFC (4.2500 GHz) | 3.4 Gbit/s | 425.00 MB/s |
| Serial Attached SCSI 2 | 6.0 Gbit/s | 600 MB/s |
| Ultra-640 SCSI | 5.12 Gbit/s | 640 MB/s |
| Note that SATA and SAS use an 8B/10B encoding scheme.
Note that Fibre Channel 1GFC, 2GFC, 4GFC use an 8B/10B encoding scheme. Note that Fibre Channel 10GFC uses a 64B/66B encoding scheme, is not compatible with 1GFC, 2GFC and 4GFC, and is used only to interconnect switches. [edit] Computer buses (external) |
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| Serial RS-232 commonly | 9.6 kbit/s | 960 B/s |
| Apple Desktop Bus | 125 kbit/s | |
| Serial RS-232 max | 230.4 kbit/s | 23.0 kB/s |
| USB Low Speed | 1536 kbit/s | 192 kB/s |
| Parallel (Centronics) | 8.0 Mbit/s | 1.0 MB/s |
| Serial RS-422 max | 10.0 Mbit/s | 1.25 MB/s |
| USB Full Speed | 12.0 Mbit/s | 1.5 MB/s |
| FireWire (IEEE 1394) 100 | 98.304 Mbit/s | 12.288 MB/s |
| FireWire (IEEE 1394) 200 | 196.608 Mbit/s | 24.576 MB/s |
| FireWire (IEEE 1394) 400 | 393.216 Mbit/s | 49.152 MB/s |
| USB Hi-Speed | 480 Mbit/s | 60 MB/s |
| FireWire (IEEE 1394b) 800 | 786.432 Mbit/s | 98.304 MB/s |
| FireWire (IEEE 1394b) 1600 | 1572.864 Mbit/s | 196.608 MB/s |
| Cameralink base 24bit 85MHz | 2.04 Gbit/s | 261.12 MB/s |
| External SATA | 2.4 Gbit/s | 300 MB/s |
| FireWire (IEEE 1394b) 3200 | 3.145728 Gbit/s | 393.216 MB/s |
|
Note that FireWire (IEEE 1394b) uses an 8B/10B coding scheme. Note that SATA uses an 8B/10B coding scheme. [edit] Wireless device connection |
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| IrDA-Control | 72 kbit/s | 9 kB/s |
| IrDA-SIR | 115.2 kbit/s | 14 kB/s |
| 802.15.4 (2.4 GHz) | 250 kbit/s | 31.25 kB/s |
| Bluetooth 1.1 | 1 Mbit/s | 125 kB/s |
| Bluetooth 2.0+EDR | 3 Mbit/s | 375 kB/s |
| IrDA-FIR | 4 Mbit/s | 500 kB/s |
[edit] Wireless networking |
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| 802.11 legacy 0.125 | 2 Mbit/s | 250 kB/s |
| RONJA free source optical wireless | 10.00 Mbit/s | 1.25 MB/s |
| 802.11b DSSS 0.125 | 11 Mbit/s | 1.375 MB/s |
| 802.11b+ non-standard DSSS 0.125 | 44.0 Mbit/s | 5.5 MB/s |
| 802.11a 0.75 | 54.00 Mbit/s | 6.75 MB/s |
| 802.11g DSSS 0.125 | 54.00 Mbit/s | 6.75 MB/s |
| 802.11n | 540 Mbit/s | 67.5 MB/s |
[edit] Mobile telephone interfaces |
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| WiDEN | ' | |
| GSM CSD | 2.4 to 14.4 kbit/s | 300 to 1800 B/s |
| HSCSD upstream | 14.4 kbit/s | 1800 B/s |
| HSCSD downstream | 43.2 kbit/s | 5.4 kB/s |
| GPRS upstream | 28.8 kbit/s | 3.6 kB/s |
| GPRS downstream | 57.6 kbit/s | 7.2 kB/s |
| EDGE downstream | 236.8 kbit/s | 29.6 kB/s |
| UMTS downstream | 1920 kbit/s | 240 kB/s |
| HSDPA downstream | 1.8 MBit/s to 14.4 Mbit/s | 225 kB/s to 1.8 MB/s |
| HSUPA downstream | ' | |
| HSOPA downstream | ' | |
| CDMA2000 1xRTT downstream | ' | |
| CDMA2000 1xRTT upstream | ' | |
| 1xEV-DO Rev. 0 downstream | 2.4576 Mbit/s | |
| 1xEV-DO Rev. 0 upstream | 0.15 Mbit/s | |
| 1xEV-DO Rev. A downstream | 3.1 Mbit/s | 396.8 kB/s |
| 1xEV-DO Rev. A upstream | 1.8 Mbit/s | 230.4 kB/s |
| 1xEV-DO Rev. B downstream | 73.5 Mbit/s | |
| 1xEV-DO Rev. B upstream | ' | |
| 1xEV-DO Rev. C downstream | 280 Mbit/s | |
| 1xEV-DO Rev. C upstream | ' | |
[edit] Wide area network |
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| DS0 | 64 kbit/s | 8 kB/s |
| Satellite Internet upstream | 64 kbit/s to 1 Mbit/s | 8 kB/s to 128 kB/s |
| Satellite Internet downstream | 128 kbit/s to 16 Mbit/s | 16 kB/s to 2 MB/s |
| Frame Relay | 8 kbit/s to 45 Mbit/s | 1 kB/s to 5.625 MB/s |
| G.SHDSL | 2.3040 Mbit/s | 0.288 MB/s |
| SDSL | 64 kbit/s to 4.608 Mbit/s | 8 kB/s to 0.576 MB/s |
| G.Lite (aka ADSL Lite) upstream | 512 kbit/s | 64 kB/s |
| G.Lite (aka ADSL Lite) downstream | 1.5 Mbit/s | 192 kB/s |
| ADSL upstream | 64 kbit/s to 1024 kbit/s | 8 kB/s to 128 kB/s |
| ADSL downstream | 256 kbit/s to 8 Mbit/s | 32 kB/s to 1 MB/s |
| ADSL2 upstream | 64 kbit/s to 3.5 Mbit/s | 8 kB/s to 448 kB/s |
| ADSL2 downstream | 256 kbit/s to 12 Mbit/s | 32 kB/s to 1.5 MB/s |
| ADSL2Plus upstream | 64 kbit/s to 3.5 Mbit/s | 8 kB/s to 448 kB/s |
| ADSL2Plus downstream | 256 kbit/s to 24 Mbit/s | 32 kB/s to 3.0 MB/s |
| DOCSIS (Cable Modem) upstream | 128 kbit/s to 8 Mbit/s | 16 kB/s to 1 MB/s |
| DOCSIS (Cable Modem) downstream | 384 kbit/s to 24 Mbit/s | 48 kB/s to 3 MB/s |
| DS1/T1 | 1.544 Mbit/s | 192.5 kB/s |
| E1 | 2.048 Mbit/s | 256 kB/s |
| T2 | 6.312 Mbit/s | 789 KB/s |
| E2 | 8.448 Mbit/s | 1.056 MB/s |
| E3 | 34.368 Mbit/s | 4.296 MB/s |
| DS3/T3 ('45 Meg') | 44.736 Mbit/s | 5.5925 MB/s |
| STS-1/EC-1/OC-1/STM-0 | 51.840 Mbit/s | 6.48 MB/s |
| VDSL (symmetry optional) | 12 Mbit/s to 100 Mbit/s | 1.5 MB/s to 12.5 MB/s |
| VDSL2 (symmetry optional) | 12 Mbit/s to 250 Mbit/s | 1.5 MB/s to 31.25 MB/s |
| LR-VDSL2 (4 to 5 km [long-]range) (symmetry optional) | 1 Mbit/s to 4 Mbit/s | 128 kB/s to 512 kB/s |
| OC-1 | 51.84 Mbit/s | 6.48 MB/s |
| OC-3/STM-1 | 155.52 Mbit/s | 19.44 MB/s |
| T4 | 274.176 Mbit/s | 34.272 MB/s |
| T5 | 400.352 Mbit/s | 50.044 MB/s |
| OC-9 | 466.560 Mbit/s | 58.32 MB/s |
| OC-12/STM-4 | 622.08 Mbit/s | 77.76 MB/s |
| OC-18 | 933.12 Mbit/s | 116.64 MB/s |
| OC-24 | 1.244 Gbit/s | 155.5 MB/s |
| OC-36 | 1.9 Gbit/s | 237.5 MB/s |
| OC-48/STM-16 | 2.488320 Gbit/s | 311.04 MB/s |
| OC-96 | 4.976 Gbit/s | 622 MB/s |
| OC-192/STM-64 | 9.953280 Gbit/s | 1.24416 GB/s |
| 10 Gigabit Ethernet WAN PHY | 9.953280 Gbit/s | 1.24416 GB/s |
| 10 Gigabit Ethernet LAN PHY | 10 Gbit/s | 1.25 GB/s |
| OC-256 | 13.271 Gbit/s | 1.65888 GB/s |
| OC-768/STM-256 | 39.813120 Gbit/s | 4.97664 GB/s |
| OC-1536/STM-512 | 79.626 Gbit/s | 9.95325 GB/s |
| OC-3072/STM-1024 | 159.252 Gbit/s | 19.9065 GB/s |
[edit] Local area network |
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| LocalTalk | 230.4 kbit/s | 28.8 kB/s |
| ARCNET (Standard) | 2.5 Mbit/s | 0.3125 MB/s |
| Token Ring (Original) | 4.16 Mbit/s | 0.52 MB/s |
| Ethernet (10base-X) | 10 Mbit/s | 1.25 MB/s |
| Token Ring (Later) | 16 Mbit/s | 2.0 MB/s |
| Fast Ethernet (100base-X) | 100 Mbit/s | 12.5 MB/s |
| FDDI | 100 Mbit/s | 12.5 MB/s |
| Gigabit Ethernet (1000base-X) | 1 Gbit/s | 125 MB/s |
| Myrinet 2000 | 2 Gbit/s | 250 MB/s |
| Infiniband 1X | 2.5 Gbit/s | 312 MB/s |
| 10 gigabit Ethernet (10Gbase-X) | 10 Gbit/s | 1.25 GB/s |
| Myri 10G | 10 Gbit/s | 1.25 GB/s |
| Infiniband 4X | 10 Gbit/s | 1.25 GB/s |
| Infiniband 12X | 30 Gbit/s | 3.75 GB/s |
[edit] Memory Interconnect Buses / RAM |
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| SPARC MBus | 2560 Mbit/s | 320 MB/s |
| PC66 SDRAM | 4264 Mbit/s | 533 MB/s |
| PC100 SDRAM | 6400 Mbit/s | 800 MB/s |
| HP Runway bus 125MHz 64-bit | 6400 Mbit/s | 960 MB/s |
| PC133 SDRAM | 8528 Mbit/s | 1066 MB/s |
| PC1600 DDR-SDRAM (single channel) | 12.8 Gbit/s | 1.6 GB/s |
| HP Runway bus 125MHz 64-bit DDR | 16 Gbit/s | 2 GB/s |
| PC1600 DDR-SDRAM (dual channel) | 25.6 Gbit/s | 3.2 GB/s |
| PC2100 DDR-SDRAM (single channel) | 16.8 Gbit/s | 2.1 GB/s |
| PC2100 DDR-SDRAM (dual channel) | 33.6 Gbit/s | 4.2 GB/s |
| PC2700 DDR-SDRAM (single channel) | 21.6 Gbit/s | 2.7 GB/s |
| PC2700 DDR-SDRAM (dual channel) | 43.2 Gbit/s | 5.4 GB/s |
| PC3200 DDR-SDRAM (single channel) | 25.6 Gbit/s | 3.2 GB/s |
| PC3200 DDR-SDRAM (dual channel) | 51.2 Gbit/s | 6.4 GB/s |
| PC4000 DDR-SDRAM (single channel) | 34.3 Gbit/s | 4.0 GB/s |
| PC4000 DDR-SDRAM (dual channel) | 68.6 Gbit/s | 8.0 GB/s |
| PC800 RDRAM (single-channel) | 12.8 Gbit/s | 1.6 GB/s |
| PC800 RDRAM (dual-channel) | 25.6 Gbit/s | 3.2 GB/s |
| PC1066 RDRAM (single-channel) | 16.8 Gbit/s | 2.1 GB/s |
| PC1066 RDRAM (dual-channel) | 33.6 Gbit/s | 4.2 GB/s |
| PC1200 RDRAM (single-channel) | 19.2 Gbit/s | 2.4 GB/s |
| PC1200 RDRAM (dual-channel) | 38.4 Gbit/s | 4.8 GB/s |
| PC2-3200 DDR2-SDRAM (single channel) | 25.6 Gbit/s | 3.2 GB/s |
| PC2-3200 DDR2-SDRAM (dual channel) | 51.2 Gbit/s | 6.4 GB/s |
| PC2-4200 DDR2-SDRAM (single channel) | 34.136 Gbit/s | 4.267 GB/s |
| PC2-4200 DDR2-SDRAM (dual channel) | 68.272 Gbit/s | 8.534 GB/s |
| PC2-5400 DDR2-SDRAM (single channel) | 42.664 Gbit/s | 5.333 GB/s |
| PC2-5400 DDR2-SDRAM (dual channel) | 85.328 Gbit/s | 10.666 GB/s |
| PC2-6400 DDR2-SDRAM (single channel) | 51.2 Gbit/s | 6.4 GB/s |
| PC2-6400 DDR2-SDRAM (dual channel) | 102.4 Gbit/s | 12.8 GB/s |
| PC2-8500 DDR2-SDRAM† (single channel) | 68.264 Gbit/s | 8.533 GB/s |
| PC2-8500 DDR2-SDRAM† (dual channel) | 164.528 Gbit/s | 17.066 GB/s |
| 2005-Feb Prototype DDR3-SDRAM | ~68.224 Gbit/s | ~8.528 GB/s |
† Not part of official standard, modules intended for overclocking enthusiasts
[edit] Notes
- 56K modem V.90 and V.92 capacity can only be achieved when the upstream (service provider) end of the connection is digital. In addition, certain telecommunications administrations limit the signal strength the modem can transmit onto the telecommunications circuit, which in turn limits the actual maximum data rate to less than the theoretical maximum. In the USA, this limited the possible downstream maximum to 53.3 kbit/s
- ISDN A basic rate interface (BRI) provides 2 'B' channels and one 'D' channel. Each B channel provides 64 kbit/s bandwidth and the 'D' channel carries signalling (call setup) information. Primary rate interfaces (PRI) vary depending on whether the region uses E1 or T1 bearers. In E1 regions, the PRI carries 30 B-channels and 1 D-channel; in T1 regions the PRI carries 23 B-channels and 1 D-channel. The D-channel has different bandwidth on the two interfaces.
- Actual frame relay connections will vary in throughput from 8 kbit/s to 45 Mbit/s depending on configuration. Most commonly below 2 Mbit/s.
- ADSL connections will vary in throughput from 64 kbit/s to several Mbit/s depending on configuration. Most commonly below 2 Mbit/s. Some ADSL & SDSL connections have a higher bandwidth than T1 but their bandwidth is not guaranteed, and will drop when the system gets overloaded where as the T1 type connections are usually guaranteed & have no contention ratios.
- DOCSIS 1.0 specifications include technology that was available in the 1995–1996 timeframe, and have become very widely deployed around the world.
- DOCSIS 1.1 specifications provide improved operational flexibility, security, and Quality-of-Service (QoS) features that enable real-time services.
- DOCSIS 2.0 specifications provide dramatically increased upstream throughput for symmetric services.
- DOCSIS 3.0 specifications are currently in development at CableLabs and will include a number of enhancements, most notably, channel bonding and support for IPv6. Channel bonding provides cable operators with a flexible way to increase upstream and downstream throughput to customers, with data rates in the hundreds of megabits and potentially gigabits per second.
- Satellite internet may have a high bandwidth but also has a high latency due to the distance between the modem, satellite & hub. One-way satellite connections exist where all the downstream traffic is handled by satellite and the upstream traffic by land-based connections such as 56K modems & ISDN.
[edit] Decimal vs. Binary Prefixes
| Bit rates | ||
|---|---|---|
| Decimal prefixes (SI) | ||
| Name | Symbol | Multiple |
| kilobit per second | kbit/s | 103 |
| megabit per second | Mbit/s | 106 |
| gigabit per second | Gbit/s | 109 |
| terabit per second | Tbit/s | 1012 |
| Binary prefixes (IEC 60027-2) |
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| kibibit per second | Kibit/s | 210 |
| mebibit per second | Mibit/s | 220 |
| gibibit per second | Gibit/s | 230 |
| tebibit per second | Tibit/s | 240 |
“Metric” (aka decimal, SI, power of 10) prefixes are commonly misused when referring to binary quantities, i.e. computer data file sizes.
“kilo” actually means one thousand, “mega” means one million, “giga” is one billion, and so on.
However, when referring to computer data quantities, people will often say “one kilobyte” or write “1 KB”, but actually mean 1024 bytes, for example.
This misuse started decades ago, essentially due to the fact that computer data quantities are based on the power of 2, yet metric prefixes, based on the power of 10, were used for these quantities. Microsoft is probably the most noteworthy responsible party - their Windows operating systems still misuse the metric prefixes.
In 1999 the IEC introduced a formal prefix standard (IEC 60027) for binary numbers, which became an IEEE standard in 2005 (IEEE-1541), ergo:
1024 bytes is a kibibyte (KiB), 1024 KiB is a mebibyte (MiB), 1024 MiB is a gibibyte (GiB), 1024 GiB is a tebibyte (TiB), etc.
For example, Kilobyte can refer to either 1000 bytes or 1024 bytes in common speech, however the IEEE has recently defined all the kibi-, mebi-, etc. prefixes to mean 1024 and the kilo-, mega-, etc. prefixes to mean 1000, to stay in line with the rest of the metric system and end the current confusion.
Much confusion and miscommunication should end when these standardized binary number prefixes come into common use.
All of the bandwidth values listed in this article are true metric quantities, i.e. a kilobit = 1000 bits, NOT 1024 bits.
