SR vs LR SFP+: 10G Optical Link Comparison

Optical Engineering Guide

A detailed breakdown of 10GBASE-SR (Short Reach, Multimode) versus 10GBASE-LR (Long Reach, Single-mode) optical transceivers.

Technical Attribute Comparison Matrix

Fiber TypeMultimode (OM3 / OM4 / OM5)Single-mode (OS1 / OS2)

Wavelength850 nm (VCSEL Laser)1310 nm (DFB Laser)

Max Distance300m (OM3) / 400m (OM4)10 km (Standard Single-mode)

Core Diameter50 µm9 µm

Typical CostLower component costModerate component cost

Best Use CaseIntra-rack, same server room, inter-floor patchInter-building campus, metro link, WAN riser

Pre-Procurement Checklist

Verify fiber patch cord jacket color (Aqua/Violet for Multimode SR vs Yellow for Single-mode LR).

Never connect an SR transceiver directly to an LR transceiver; wavelengths (850nm vs 1310nm) are incompatible.

Check switch port SFP+ compatibility list before ordering.