Linear Pluggable Optics

Overview

Linear Pluggable Optics (LPO) is a pluggable transceiver variant that removes the DSP (digital signal processing) retimer from the optical module, relying instead on the host ASIC's SerDes for equalization. Because DSP previously accounted for approximately 40% of transceiver module power, eliminating it delivers the lowest power and latency of any pluggable optics architecture — but at the cost of reduced diagnostics, tighter link engineering requirements, and interoperability only within LPO MSA-defined specifications.

At 800G DR8, LPO modules measure 7.5 W average (9.4 pJ/bit) versus 8.5 W for LRO and 13.0 W for DSP. At 1.6T 2xDR4, LPO is 10.0 W (6.3 pJ/bit) versus 15.0 W for LRO and 21.0 W for DSP — the efficiency gap widens at higher data rates, making LPO increasingly attractive as bandwidth scales. Accelink demonstrated consistent BER well within 1E-9 across all 64 ports of a switch using 800G DR8 LPO, validating production-level consistency across varying port channel lengths.