USFP vs co-packaged optics
Co-packaged optics save the most power. Pluggables like USFP keep the thing operators value most: pulling out a failed module.
The long electrical path from a switch chip to a front-panel module costs power: the signal has to be driven across the board, and the module usually has a DSP to clean it up. Co-packaged optics (CPO) remove that path by putting the optical engines inside the switch chip's package. Near-package optics (NPO) put them in sockets right beside it. USFP is the case for keeping optics at the front panel anyway.
Three places to put the optics
| Pluggable (USFP) | Socketed (Open CPX) | Co-packaged (CPO) | |
|---|---|---|---|
| Where | Front panel | Socket next to the chip | Inside the chip package |
| Replace a failed one | From the front, switch running | Open the box, swap the engine | Not field-replaceable |
| Power per bit | Highest of the three | Lower | Lowest |
| Buy optics separately | Yes, from any maker that follows the MSA | Yes, to the Open CPX spec | Comes with the switch |
| Status | Announced Oct 2026 | Spec released Sep 2026 | NVIDIA shipping to select partners |
Sources: NAND Research, Open CPX MSA, TrendForce.
Why operators still like pluggables
Optics fail more often than switch chips. With a pluggable, a technician pulls the bad module and pushes in a new one in a minute, and the operator can buy modules from several suppliers. With CPO, the optics are part of the switch. NAND Research notes many large operators prefer keeping front-panel swaps and separate procurement of optics and switches, and that CPO couples you more tightly to one vendor (NAND Research). Cisco's own launch post leans on the same point: USFP keeps existing pluggable operating practices.
NVIDIA backs both
NVIDIA builds CPO switches (Spectrum-X Photonics, which TrendForce reported in July 2026 was shipping to select partners) and co-developed USFP. NAND Research calls USFP a hedge: a pluggable path for customers not ready for CPO, with NVIDIA's SerDes and network cards at the center either way.
Open CPX, the middle road
The Open CPX MSA, founded by Ciena, Coherent, Marvell, Molex, Samtec and TeraHop, released its specification on September 17, 2026: socketed optical engines of 6.4T or 7.2T at 200G per lane, with liquid-cooling specifications (Open CPX MSA). Engines can be replaced, but from inside the box rather than the front panel.
Which wins
Probably all three, in different places. CPO where power is the hard limit and one vendor supplies the whole system; socketed optics where operators want lower power but replaceable parts; pluggables like USFP and XPO where serviceability and a multi-vendor supply chain matter most. Counterpoint expects both USFP and XPO to face CPO competition as lanes reach 400G and 800G (Counterpoint Research).
USFP vs OSFP
Same footprint, four times the bandwidth, a new connector. Why your OSFP cages won't take it.
USFP vs XPO
Air-friendly 6.4T against a liquid-cooled 12.8T. Two camps, two bets on the next switch chip.
Every form factor
OSFP to co-packaged optics in one table: lanes, capacity, heat and who backs each.
Sources
- Cisco and NVIDIA: Optical Ultra-Dense Small Form Factor Pluggable (USFP) Specification, NAND Research, October 13, 2026.
- Open CPX MSA Group Releases Specification for High Density, Pluggable CPO/NPO, Open CPX MSA (Business Wire release), September 17, 2026.
- NVIDIA begins shipping Spectrum-X CPO switch to select partners, TrendForce, July 27, 2026.
- Cisco and NVIDIA Launch Ultra-Dense Small Form Factor Pluggable (USFP), Counterpoint Research, October 16, 2026.
- Cisco and NVIDIA Announce USFP: Expanding the Path to AI Connectivity, Cisco Blogs (Bill Gartner and Will Eatherton), October 12, 2026.