Copper or fiber? This is one of the big questions in network cabling. Each has its strengths: copper (RJ45) is simple and economical, while fiber excels in speed and distance. This guide compares the two to help you choose.
Copper Cable (Ethernet RJ45)
Twisted pair copper (Cat5e, Cat6, Cat6a) remains the standard for connecting workstations, switches, and devices over short distances. Its advantages: low cost, easy to install, and it supports PoE (Power over Ethernet). Its limitation: a maximum of 100 meters per link and sensitivity to electromagnetic interference.
Optical Fiber
Fiber transmits light rather than electricity: very high speed, total immunity to interference, and long distances. Two types: multimode fiber (short to medium distances, internal cabling and data centers) and single-mode fiber (long distances, links between buildings or sites).
Speed and Distance
| Medium | Current Speed | Max Distance |
|---|---|---|
| Copper Cat6 | 1 Gbps (10 Gbps up to ~55 m) | 100 m |
| Copper Cat6a | 10 Gbps | 100 m |
| Multimode Fiber | 10 Gbps and above | ~300 to 400 m |
| Single-mode Fiber | 10 to 100 Gbps | several kilometers |
When to Choose One or the Other
- Copper: workstations, short distances, PoE devices (cameras, Wi-Fi access points, phones).
- Fiber: uplinks, network core, links between buildings, industrial environments with interference.
Hardware: SFP Modules
To switch to fiber, use SFP or SFP+ ports on the switch, into which you insert compatible transceiver modules (multimode or single-mode). See our SFP & transceiver modules and our guide SFP, SFP+, and QSFP.
FAQ
Is fiber always faster than copper?
At equal speeds (e.g., 10 Gbps), both perform similarly; fiber stands out mainly for distance and immunity to interference.
Can copper and fiber be mixed?
Yes, it is actually the standard: copper for workstations, fiber for uplinks, connected via SFP ports or media converters.
Does PoE work over fiber?
No, PoE is a copper technology. On a fiber link, local power or a PoE switch at the end is required.
To build your network, browse our network switches and SFP modules, and read our Ethernet switch guide.