For sale: a genuine NVIDIA 4-slot NVLink bridge for a pair of RTX 3090 or RTX 3090 Ti cards. This is the high-bandwidth bridge — part P3657, NVIDIA part number 900-13657-2500-000 — not the shorter 3-slot version.

The 4-slot bridge has become very hard to find, and prices for used examples have climbed with demand for dual-3090 AI builds. This is the bridge from my dual-3090 machine, Shadowfax, where it was in daily use — and it comes with its original box and leaflet.

RTX 3090 is the only GeForce card of its generation with NVLink. With the bridge fitted, the two GPUs get a direct high-bandwidth link instead of sending everything over PCIe. That matters for tensor-parallel inference, where the cards have to exchange activations and all-reduce results on every layer.

It does not merge the two 24 GB frame buffers into one 48 GB allocation. Each card still has 24 GB, but the cards can access each other’s memory peer-to-peer and move data much faster than over PCIe.

Specifications

Item Specification
Type NVIDIA NVLink High Bandwidth (HB) bridge
Spacing 4-slot
NVIDIA part number 900-13657-2500-000
Model / revision P3657
Links 4 per GPU pair
Link speed 14.062 GB/s per link
Aggregate About 56 GB/s per direction, about 112 GB/s bidirectional
Topology reported by nvidia-smi NV4
Supported cards NVIDIA GeForce RTX 3090 and RTX 3090 Ti

Fit and compatibility

  • Fits RTX 3090 and RTX 3090 Ti only. RTX 3080, 3080 Ti and the rest of the 30-series do not support NVLink.
  • This is the 4-slot spacing version. Check the distance between the NVLink fingers on your two cards before buying: a 3-slot bridge is visibly shorter and will not reach across a 4-slot gap.
  • Both cards need to be oriented the same way, as usual for an NVLink bridge.
  • No drivers or software are required; the bridge is passive. nvidia-smi topo -m should report NV4 once it is fitted and both cards are visible.

Condition

  • Used, genuine NVIDIA part, removed from Shadowfax, my dual-RTX-3090 workstation.
  • Proven working in daily use — the video below shows it installed and running in Shadowfax.
  • Tested in that machine: nvidia-smi topo -m reports NV4, and nvidia-smi nvlink -s shows all four links active at 14.062 GB/s on each GPU.
  • Original NVIDIA box and leaflet included.
  • No cracks, no bent or damaged connector fingers. Cosmetic wear is minimal.
  • It has now been removed and will be packed carefully for shipping.

Photos and video

Original NVIDIA box, leaflet and foam tray with the NVLink bridge
Original box, leaflet and foam tray.
Lid of the NVIDIA GeForce RTX NVLink Bridge box
Box lid: NVIDIA GeForce RTX NVLink Bridge.
Box label showing model P3657 and part number 900-13657-2500-000
Box label confirming P3657 and part 900-13657-2500-000.
Top side of the NVIDIA 4-slot NVLink bridge
The 4-slot bridge, top side.
Connector side of the NVLink bridge, showing the two NVLink fingers
Connector side, showing the two NVLink fingers.
NVLink bridge installed between two EVGA RTX 3090 cards in Shadowfax
Previously installed between the two EVGA RTX 3090s in Shadowfax.
The bridge running in Shadowfax before removal.

Price and shipping

US$1,000 (≈ C$1,410) or nearest offer.

Pickup in Vancouver, BC, or shipping worldwide at the buyer's expense. It is small and light, so tracked international shipping is inexpensive. Payment can be made in USD or CAD.

CAD price is approximate, converted at US$1 ≈ C$1.41 on 10 November 2026.

Payment by PayPal G&S, Interac e-transfer, or cash on pickup. If you are buying the dual RTX 3090 workstation, I can include this bridge with the machine instead — get in touch and we can work out a bundle.