compare
Pluggable optics
Co-packaged optics
Why co-packaged optics save power: the DSP stage and long electrical path versus a die-adjacent optical engine
Pluggable optics
long PCB electrical trace + DSP retimer inside each module
faceplate
transceiver module
laser
light in
DSP
DSP retimer: burns power, adds latency
loss grows
long PCB electrical trace
switch ASIC
Co-packaged optics
optical engine moves onto the switch package, adjacent to the ASIC
external
light source
kept separate
switch package
switch ASIC die
optical engine
co-located with ASIC
no DSP, µm-scale path
fiber
to fabric
lower power per bit
reduced switch heat load
fewer parts that can fail
light source kept separate