NVIDIA OSFP Part-Number Crosswalk: Mellanox MMA/MMS to NVIDIA 980- Numbers

NVIDIA is transitioning its transceiver and cable catalog from Mellanox part numbers to NVIDIA part numbers. Old BOMs and purchase histories carry the Mellanox number. New quotes increasingly carry the NVIDIA one. They are the same physical parts, and for a while yet you will see both in the same procurement thread.

This page is the crosswalk. It maps the OSFP 400G and 800G multimode range to form factor, optics, reach and — the part most catalogs leave out — which end of the link each part belongs in.

Working from a quote or a PO right now? Send us the part number and the switch and NIC models. We will tell you whether it is the right part, including when the answer is one we do not sell. Ask us →

The crosswalk

Mellanox P/N NVIDIA P/N Form factor Speed Optics Connector Reach Belongs in
MMA4Z00-NS400 980-9I51S-00NS00 Single-port OSFP, Flat-Top (RHS) 400G (4 × 106.125G PAM4) SR4, 850nm multimode MPO/MTP-12 APC 30m OM3 / 50m OM4 ConnectX-7, ConnectX-8, BlueField-3, DGX NIC ports
MMA4Z00-NS not yet confirmed Twin-port OSFP, Finned-Top (IHS) 800G (8 × 106.125G PAM4) SR8 (2 × SR4), 850nm multimode Dual MPO/MTP-12 APC 30m OM3 / 50m OM4 Quantum-2 air-cooled switch ports (QM9700, QM9790)
MMA4Z00-NS-FLT not yet confirmed Twin-port OSFP, Flat-Top 800G SR8, 850nm multimode Dual MPO/MTP-12 APC 30m OM3 / 50m OM4 Liquid-cooled switch ports — cold plate needs a flat surface
MMA1Z00-NS400 not yet confirmed QSFP112 — not OSFP 400G SR4, 850nm multimode MPO/MTP-12 APC — QSFP112 ports. Will not physically fit an OSFP cage.
MMS4X00-NS400 not yet confirmed Single-port OSFP 400G DR4, 1310nm single-mode MPO/MTP-12 APC 500m Single-mode plants. Different fiber entirely.
MMS4X00-NM / MMS4X00-NS not yet confirmed Twin-port OSFP 800G DR8, single-mode Dual MPO/MTP-12 APC 500m class Single-mode plants.

On the blanks: we publish an NVIDIA part number only where we have confirmed it with a supplier. 980-9I51S-00NS00 is confirmed for MMA4Z00-NS400. The rest are marked unconfirmed rather than guessed, because a wrong part number on a PO is the exact problem this page exists to prevent. We add them as they are confirmed — ask us if you need one of them today and we will go get it.

How to read these part numbers

Three characters do almost all the work.

Segment What it tells you
MMA vs MMS MMA is multimode (850nm, SR, OM3/OM4, short reach). MMS is single-mode (1310nm, DR, 500m+). This is the single most consequential character in the string, and it decides which fiber plant the part belongs to.
4Z00 vs 1Z00 vs 4X00 The family, which carries the cage. 4Z00 and 4X00 are OSFP. 1Z00 is QSFP112 — a physically different cage that will not seat in an OSFP port no matter what the rest of the number says.
-NS400 vs -NS Port count and speed. -NS400 is single-port 400G. -NS is twin-port 800G presenting as 2 × 400G.
-FLT suffix Flat-top build of a part that is otherwise finned. Exists for liquid-cooled deployments.

The heatsink tells you which end of the link

This is the part that costs people money, and it is not a spec — it is a fit constraint.

Old / colloquial name Current NVIDIA term What it means
Flat-top, flat RHS — Riding Heat Sink The equipment's heatsink rides on top of the module. The module is flat because the port cage has the cooling.
Finned-top, finned IHS — Integrated Heat Sink The fins are integrated into the module's own metal top, because the port has no cooling of its own.

The fins are either on the module or on the equipment. Never both, never neither.

  • A finned module in a ConnectX-7 will not seat — the cage heatsink is in the way.
  • A flat module in an air-cooled switch seats fine and looks like it worked. There is just no cooling path.
  • A finned module in a liquid-cooled switch defeats the cold plate, which needs a flat contact surface.

The canonical topology: one twin-port finned module in the switch → two MPO-12/APC patch cords → two flat-top modules in two ConnectX-7 servers. One switch module serves two servers — for every two server ports, one switch module.

The wrong-order list

Part ordered Why it gets ordered What actually happens
MMA4Z00-NS (finned) for a NIC "800G is better than 400G" Won't seat under the cage heatsink. And the ConnectX-7 OSFP port is a 400G port — the extra 400G was never available at that end.
MMA4Z00-NS400 (flat) for an air-cooled switch Assumed flat is universal Seats, links, no cooling path. The failure is thermal and it shows up later.
MMA4Z00-NS (finned) for a liquid-cooled switch Didn't know the -FLT variant exists Fins defeat the cold plate. MMA4Z00-NS-FLT is the correct part.
MMA1Z00-NS400 Same "NS400" suffix, similar description QSFP112 cage. Will not physically fit an OSFP port.
MMS4X00-NS400 One character different from MMA4X00 Single-mode DR4 at 1310nm. Wrong fiber plant.

What we stock

New, lifetime warranty backed by Resilient Tec, shipping from Knoxville, Tennessee.

We do not stock the flat-top 800G (MMA4Z00-NS-FLT) or the MMS single-mode range. If that is what your build needs, that is what we will tell you.

Populating a cluster? Tell us the port count and we will quote the switch-side and server-side modules together. In-stock quantities are small by design; additional units ship on a 7–10 day lead time.

Related reading

You might also need