Short answer: for the NVIDIA MMA4Z00-NS400 / 980-9I51S-00NS00 flat-top (RHS) 400G OSFP SR4 module — the one that goes into a ConnectX-7 or ConnectX-8 adapter, a BlueField-3 DPU, or a DGX system — U.S. pricing for a compatible module currently runs from $579 to $769, and genuine NVIDIA OEM stock through authorized distribution runs $883 to $1,535. Where a given seller falls in that range usually comes down to three things: whether the module is genuine OEM or compatible, how many hands it passed through before it reached you, and whether anyone actually coded and tested it against ConnectX-7 before it shipped.
Here's the fuller picture, and where it's easy to get burned even after you've picked a price. Populating the switch side of the same link? See the MMA4Z00-NS 800G pricing guide for the finned-top module this one pairs with.
U.S. Pricing Comparison — MMA4Z00-NS400 Flat-Top (RHS)
| Supplier | Price | Type | Fulfillment |
|---|---|---|---|
| Resilient Tec | $579.00 | Compatible, coded for ConnectX-7 | Knoxville, TN — in stock, online checkout |
| HPC Optics | $599.00 | Compatible | Chicago, IL |
| FS.com | $769.00 | Compatible | New Castle, DE / City of Industry, CA |
| ServerSupply | $850 – $990 | Surplus / open-box, genuine OEM | New York, NY |
| ServerOrbit | $883.50 | Genuine OEM | US domestic stock |
| eSaitech | $943.00 | Genuine OEM | US domestic stock |
| Insight | $1,035.99 | Genuine OEM, new | US authorized distribution |
| Connection (PC Connection) | $1,130.09 | Genuine OEM, new | US enterprise fulfillment |
| Colfax Direct | $1,535.00 | Genuine OEM, new | California — AI/HPC integrator |
Prices observed the week of August 25, 2026, and change without notice — verify current pricing and stock before ordering from any listed source, including us.
In stock: 1 · $579.00 · Additional units ship on a 7–10 day lead time.
Building a cluster? Tell us how many ports you are populating and we'll quote the switch-side and server-side modules together. Request a quote →
Genuine OEM vs. Compatible: What the Price Gap Actually Buys
The $500 gap between the cheapest compatible module and Colfax's OEM listing isn't padding — it's two different supply chains. Genuine NVIDIA OEM stock carries NVIDIA's factory firmware, ships through an authorized distribution tier, and usually rides on a corporate account with volume terms baked into list price. That's the right call if procurement policy requires OEM part numbers on the PO, or if the deployment is under a support contract that specifies factory optics.
Compatible modules are built to the same OSFP MSA and SR4 optical spec on third-party hardware, then coded to answer the host's firmware handshake the way the OEM module would. The coding step is where compatible modules succeed or fail — a module that isn't coded for the specific host platform can get flagged or rejected even though the optics are fine. That's a real failure mode, not a theoretical one, and it's why "compatible" spans a $260 range on its own: some sellers test against ConnectX-7 and NDR InfiniBand specifically, others sell one SKU across every OSFP host and let the customer find out which switches accept it.
The Other Way to Get This Wrong: Flat-Top vs. Finned-Top
Price isn't the only place this part number trips people up. MMA4Z00-NS400 covers a flat-top (RHS) module built for the NIC side of the link — ConnectX-7, ConnectX-8, BlueField-3, DGX — and a separate finned-top (IHS) module built for air-cooled Quantum-2 switches. The fins live on whichever side doesn't already have a heatsink built into the port cage; a finned module physically will not seat in a ConnectX-7 OSFP port, and a flat-top module won't provide the cooling a switch port needs. One switch-side finned module typically serves two server-side flat-top modules over MPO-12/APC patch cords — see the 800G OSFP SR8 pricing guide for that module's own cost breakdown.
Every listing in the table above is priced against the flat-top module specifically. If a price looks unusually low, confirm which variant is actually being quoted before comparing it — a finned-top listing at a lower price isn't a better deal, it's the wrong part.
If you aren't certain which variant your ports take, settle that before you spend anything — it takes about two minutes: Flat-Top or Finned-Top OSFP? How to Tell Which Module Your ConnectX-7 Actually Needs covers the rule, the RHS/IHS renaming, and the near-miss part numbers that won't physically fit an OSFP cage.
Why the Cheapest Listing Isn't Always the Riskiest One
Marketplace listings (eBay, cross-border sellers on aggregator feeds) can undercut every price in this table, and that's exactly where "compatible" stops meaning tested-and-coded and starts meaning unknown provenance. The meaningful comparison isn't compatible-vs-OEM, it's tested-and-warrantied vs. untested, regardless of which category a seller falls into. A module coded for ConnectX-7, backed by a real warranty, and sold by someone who answers the phone when it fails is worth more than the sticker price implies — and it's also why this comparison sticks to name-brand U.S. distributors and stocking sellers rather than marketplace listings with no traceable seller behind them.
FAQ
Is a compatible MMA4Z00-NS400 as good as genuine NVIDIA OEM?
Optically, a properly built compatible module meets the same SR4 spec. The differentiator is coding and testing against the specific host platform — ConnectX-7, ConnectX-8, BlueField-3, DGX — and what happens when a module fails. OEM stock makes sense when a support contract or procurement policy requires it; compatible modules make sense everywhere else, provided the seller actually validates against your platform.
Why is there such a wide price range for the same part number?
Genuine OEM pricing reflects NVIDIA's factory firmware and authorized distribution overhead. Compatible pricing reflects how much testing, coding, and support backs the module — plus ordinary distributor markup. Marketplace listings outside this comparison can go lower still, at the cost of any of that.
Do I need the flat-top or finned-top version?
Flat-top (RHS) for anything on the NIC or DPU side — ConnectX-7, ConnectX-8, BlueField-3, DGX. Finned-top (IHS) for air-cooled Quantum-2 switches. Flat-top or finned-top? walks the decision in full, and the NVIDIA OSFP part-number crosswalk has the full mapping.
What's covered under warranty?
Resilient Tec backs this module with a lifetime warranty — reachable directly, not routed through a manufacturer ticket queue.
Resilient Tec stocks and tests the MMA4Z00-NS400 flat-top module coded specifically for ConnectX-7 and ConnectX-8, ships from the US, and backs it with a lifetime warranty. Populating more than a handful of ports? Request a quote and we'll price the switch-side and server-side modules together.
Ready to Buy?
New, coded specifically for NVIDIA/Mellanox, shipping from Knoxville, Tennessee. Lifetime warranty, backed by Resilient Tec.
- 400G OSFP SR4 Flat-Top (RHS) — MMA4Z00-NS400 / 980-9I51S-00NS00 compatible — the module this guide prices, for ConnectX-7, ConnectX-8, BlueField-3 and DGX ports
- 800G OSFP SR8 Finned-Top (IHS) — MMA4Z00-NS compatible — the switch-side half of the same link, for air-cooled Quantum-2
- NVIDIA OSFP part-number crosswalk — check a part number against your ports before the PO goes out
Populating a cluster? Tell us the port count and we'll quote the pair together — remember it's one switch-side module for every two servers. Running single-mode, or building liquid-cooled? Ask — we'd rather point you at the right part than sell you the wrong one.
You might also need
- Flat-top vs finned-top OSFP — the technical decision behind this price comparison
- MPO-12/APC multimode patch cords, Type B polarity — the fiber between a transceiver pair
- OSFP DAC cables — when the run is short enough that copper beats optics entirely
- Optical transceivers guide — 1G SFP through 800G OSFP, across platforms
- Network switches — Arista, Cisco, HPE/Aruba and Mellanox, new and tested pre-owned
- Cat8 and structured cabling for the rest of the rack