400G/800G AOC vs Pluggable Optics and Passive Fiber Cabling

Direct answer

An AOC bonds fiber to its transceiver ends, while pluggable optics retain detachable optical connections. Select by host support, installation route, patching and replacement needs, not just a 400G/800G label or unit price.

What is being compared

NVIDIA defines an AOC as fiber bonded inside transceiver ends that perform electrical-to-optical conversion. A passive MPO or LC cord excludes those transceivers. Compare complete host-to-host bills of materials rather than unlike individual parts. NVIDIA definitions

For fixed endpoints and a route that can accommodate whole-assembly replacement, consider an AOC. For patch panels, segmented maintenance or a reusable backbone, evaluate detachable optics and fiber. These are project-review recommendations, not universal product rankings.

A bounded 400G example

Cisco lists QDD-400-AOCxM QSFP-DD assemblies in discrete lengths between 1 m and 30 m and states that FEC is performed on the host. Those details apply to that series, not every 400G or 800G AOC. Cisco 400G data sheet

The archived NVIDIA DOCA 3.1.0 support list includes third-party 800G-to-dual-400G AOC examples. Treat that as a version-specific record, not proof of support on another host or current firmware. Verify the exact assembly and platform combination. Version-specific support list

Buyer comparison

The table is an editorial review framework, not a price or performance guarantee.

Review item	AOC assembly	Pluggable optics and passive fiber
Ordering unit	Whole assembly and both host ends	Two optics and the cable separately
Intermediate patching	Establish whether optical patch points are needed	Define panels and connection count
Replacement	Review access for the entire assembly	Review separate optic or segment replacement
Installation space	Check end-head size and protection	Check connectors, pulling protection and route
Spares	Manage actual lengths and end types	Manage optics, cords and trunks separately
Acceptance	Host support and whole-link records	Cabling tests plus host-link records

Three site questions before quotation

Can the complete assembly be installed and removed along the route? Include entry points, turns and planned service slack. A nominal assembly length is not simply a straight-line separation.

Will endpoints move or require intermediate optical patching? Draw the route and mark every active end and detachable connection before selecting an architecture.

Can replacement fit the maintenance window? Compare complete materials, spares and replacement tasks for the same link. Comparing a passive cord price with an AOC price omits the optics and changes the scope.

Procurement FAQ

Can an AOC replace any MPO trunk? No blanket substitution follows. Check host support, route, patching and replacement access.
Do identical QSFP-DD ends prove compatibility? No. Verify part IDs, rate modes and platform/software support.
Are AOCs always cheaper or lower-power? No universal conclusion is justified. Compare formal specifications and complete project costs under equivalent conditions.
Does an 800G AOC automatically support two 400G ports? Only if both the specific assembly and hosts support that breakout configuration.
What is needed for the passive-fiber alternative? Supply both optic IDs, optical interfaces, fiber type, route, connection count and acceptance requirements.

Prepare a configuration review

Provide a host-to-host drawing, equipment and optic IDs, software versions, route lengths, patch points and replacement constraints. The related ARRANEX pages support passive-fiber configuration review and do not establish an AOC or transceiver supply offering.

Sources and review date

Sources checked on 2026-10-10. Manufacturer examples apply only to the cited products. Selection tables and procurement records are editorial recommendations, not ARRANEX performance, certification or supply commitments.

Sources checked: 2026-10-10