FireWire — also known as IEEE 1394, i.LINK, and Lynx — is the connection standard that USB tried to replace and never quite succeeded. While most consumers haven't seen a FireWire port in over a decade, the technology remains essential in professional video production, audio recording, and industrial applications. If you work with vintage camcorders, professional audio interfaces, or older Mac equipment, FireWire is still very much alive.
Here's what those distinctive 4-pin, 6-pin, and 9-pin connectors mean, and why FireWire refuses to fully disappear.
A brief history
FireWire was developed by Apple in the late 1980s and standardized as IEEE 1394 in 1995. Sony adopted it under the name "i.LINK" for their camcorders and PlayStation 2 (yes, the PS2 has a FireWire port). Apple included FireWire on every Mac from 1999 through about 2008, when Thunderbolt began replacing it.
For nearly two decades, FireWire was the gold standard for high-speed real-time data transfer — particularly for digital video, where USB's bursty data flow caused issues with constant streams of camcorder footage.
The three FireWire connector types
4-pin (FireWire 400, no power) — The smaller connector found on consumer camcorders, especially Sony DV and miniDV models, JVC and Canon camcorders, and some Sony VAIO laptops. The 4-pin connector carries data only — no power. This is the version Sony branded as "i.LINK."
6-pin (FireWire 400, with power) — The original FireWire connector, larger and rectangular with a tapered/notched corner. Carries data plus 8-30V DC power for connecting bus-powered devices like external hard drives. Found on older Macs, desktop PC FireWire cards, and some early prosumer camcorders.
9-pin (FireWire 800) — The newer connector for FireWire 800. Square-ish with a distinct orientation. Carries data at twice the FireWire 400 speed plus power. Found on Mac Pro towers, MacBook Pros from 2008-2011, and high-end professional equipment.
FireWire 400 vs FireWire 800
FireWire 400 (IEEE 1394a) — 400 Mbps maximum data rate. Released in 1995. Used the 4-pin and 6-pin connectors.
FireWire 800 (IEEE 1394b) — 800 Mbps maximum data rate. Released in 2002. Used the 9-pin connector.
There's also FireWire S1600 (1.6 Gbps) and S3200 (3.2 Gbps) defined in later IEEE 1394 specifications, but these saw limited adoption.
For comparison: USB 2.0 is 480 Mbps (slower than FireWire 400), USB 3.0 is 5 Gbps, and Thunderbolt 1 is 10 Gbps.
What makes FireWire different from USB?
Despite USB now being faster on paper, FireWire has technical advantages that kept it relevant for specific applications:
Peer-to-peer architecture — FireWire devices can communicate directly with each other without going through a host computer. USB requires a host. This made FireWire ideal for daisy-chaining multiple devices, like a row of audio interfaces in a recording studio.
Sustained throughput — FireWire delivers consistent, isochronous data transfer perfect for streaming applications like video. USB 2.0 had to interrupt the data flow periodically, which caused issues with realtime streams. While USB 3.0 improved this, the original USB 2.0 isochronous limitations are why videographers stuck with FireWire long after USB seemed faster.
Higher per-channel bandwidth — FireWire channels could be reserved for guaranteed bandwidth, ensuring no dropouts. Critical for multi-track audio recording and uncompressed video.
Real-time control — Industrial camera systems and machine vision applications use FireWire for its predictable, deterministic timing.
Where FireWire is still used in 2026
Vintage and prosumer camcorders — DV, miniDV, HDV, and DVCPRO camcorders use FireWire for video transfer. If you're digitizing old family videos or working in archival video preservation, you need FireWire.
Professional audio interfaces — Some pro audio gear, especially older Apogee, MOTU, and RME interfaces, uses FireWire 400 or 800. Studios with these interfaces continue to need FireWire connectivity.
Industrial cameras — Machine vision cameras for manufacturing inspection often use IEEE 1394b for its real-time guarantees.
Legacy Mac systems — Mac Pro towers from 2006-2012, MacBook Pros from 2008-2011, and various external storage systems still in use for archival work.
Legacy storage — External hard drive enclosures with FireWire interfaces, still in use for archive storage in studios and small businesses.
Connecting FireWire to modern computers
Modern computers don't have FireWire ports. To connect FireWire equipment to a current Mac or PC, you have several options:
Thunderbolt to FireWire 800 adapter — Apple's official adapter (and clones from other vendors) provides a 9-pin FireWire 800 connection from a Thunderbolt 1/2 port. With a Thunderbolt 3-to-Thunderbolt 2 adapter, this can chain to USB-C Macs.
PCIe FireWire card — Desktop PCs and Mac Pro towers can install a PCIe expansion card with FireWire 400 and 800 ports. The most popular cards use Texas Instruments chipsets, which are widely compatible.
ExpressCard FireWire adapter — For older laptops with ExpressCard slots.
USB to FireWire adapters? — These don't really work for video applications. FireWire's special timing requirements aren't satisfied by USB-based adapters. Some basic USB-to-FireWire bridges exist for storage applications but won't reliably capture video from a camcorder. Always use a true Thunderbolt or PCIe adapter for video work.
Common FireWire cables
4-pin to 6-pin cable — Connects a 4-pin camcorder to a 6-pin computer port. The most common consumer FireWire cable.
6-pin to 6-pin cable — Connects two FireWire 400 devices, like a Mac to an external hard drive.
4-pin to 4-pin cable — Used in i.LINK camcorder-to-camcorder transfers.
9-pin to 9-pin cable (FireWire 800) — For FireWire 800 device-to-device connections.
9-pin to 6-pin cable — Connects FireWire 800 to FireWire 400 equipment, allowing FireWire 800 hosts to communicate with older 400-speed devices.
9-pin to 4-pin cable — Connects FireWire 800 hosts to camcorders with the small 4-pin port.
Buying FireWire cables
Quality matters with FireWire cables. The high-speed signaling (especially with FireWire 800) is sensitive to cable quality. Look for proper double-shielding, oxygen-free copper conductors, and proper impedance matching. Cheap FireWire cables can cause dropped frames during video transfer or device disconnections.
For most applications, 6-foot cables are standard. Longer FireWire 400 cables work up to 4.5 meters; FireWire 800 is similar. Daisy-chaining devices is fine, but the total cable length in a chain shouldn't exceed about 17 meters.
At Kentek, we still carry FireWire cables in all common configurations — 4-to-4, 4-to-6, 6-to-6, 9-to-9, 9-to-6, and 9-to-4 — for the millions of FireWire devices still in use across video production, audio recording, and legacy computing.