What kind of fiber optic cable is best to run inside the computer room

For indoor computer rooms, OM4 multimode fiber or OS2 singlemode fiber with plenum-rated jackets are generally the best choices for high-speed, safe, and reliable connectivity.

Fiber Type Selection

Multimode Fiber (MMF) is ideal for short-distance connections within a computer room or data center. OM4 multimode fiber, with a 50µm core, supports high-speed data transmission up to 100 Gbps over distances up to 150 meters, making it suitable for server-to-switch or switch-to-switch links . OM5 is an advanced multimode option optimized for shortwave wavelength division multiplexing (SWDM), allowing multiple wavelengths over the same fiber for added flexibility . Singlemode Fiber (SMF), such as OS2, is better for longer runs or future-proofing your network. It has a smaller core (8–10µm) and supports high-bandwidth transmission over kilometers with minimal signal loss, making it ideal for backbone connections or links that may extend beyond the computer room .

Cable Jacket and Safety Ratings

Indoor fiber cables must meet fire safety standards. Plenum-rated cables (OFNP) are recommended for air-handling spaces, as they resist flame propagation and produce low smoke in case of fire . Riser-rated cables (OFNR) are suitable for vertical runs between floors but are less critical for a single computer room. Ensure the jacket material is flexible and lightweight for easy installation in racks and conduits .

Connector and Configuration

• Duplex cables are standard for full-duplex communication, with one fiber for transmit and one for receive .
• Simplex cables are used for unidirectional or bidirectional transceivers.
• Common connectors include LC, SC, and MPO/MTP, chosen based on transceiver compatibility and space constraints .

Summary Recommendation

For most computer room installations:

• Short-distance, high-speed links: OM4 multimode fiber, plenum-rated, duplex LC connectors.
• Long-distance or future-proof backbone: OS2 singlemode fiber, plenum-rated, duplex LC or MPO connectors. This combination ensures high bandwidth, low latency, compliance with fire codes, and flexibility for future upgrades .