Broadcom BCM85667 vs BCM85668: 16-Lane or 8-Lane PCIe Gen6 Retimer?
Broadcom BCM85667 vs BCM85668: 16-Lane or 8-Lane PCIe Gen6 Retimer?
Quick answer: Choose the BCM85667 when one device must retime an x16 PCIe Gen6 link. Choose the BCM85668 when the required link is x8 or narrower. Both are Broadcom PCIe Gen6 and CXL 3.1 retimers; the main selection difference is lane count and the supported grouping of those lanes. A retimer improves a link's signal path but does not create additional PCIe endpoint ports.
BCM85667 vs BCM85668 at a glance
| Specification | BCM85667 | BCM85668 |
|---|---|---|
| Data lanes | 16 | 8 |
| Documented lane groupings | 1 × x16; 2 × x8; 4 × x4; 8 × x2 | 1 × x8; 2 × x4; 4 × x2 |
| Interfaces | PCIe Gen6 and CXL 3.1; supports earlier PCIe generations | PCIe Gen6 and CXL 3.1; supports earlier PCIe generations |
| Maximum stated PCIe Gen6 signaling rate | 64 GT/s per lane | 64 GT/s per lane |
| Package in manufacturer brief | 8.9 × 22.8 mm, 354-ball BGA | 8.5 × 13.4 mm, 332-ball BGA |
| Ambient temperature in manufacturer brief | −40°C to +85°C | −40°C to +85°C |
| Listed ordering codes | BCM85667A0IEFB1G / BCM85667A0IEFB2G | BCM85668A0IEFB1G / BCM85668A0IEFB2G |
The B1G and B2G suffixes denote different integrated AC-capacitor options in Broadcom's ordering tables. Confirm the required option against the complete manufacturer documentation before ordering. The packages have different dimensions and ball counts, so the two devices should not be treated as a direct board-level replacement.
Which lane count fits the design?
Use BCM85667 for an x16 path. It can retime one x16 link, or be configured for supported groups such as two x8 links or four x4 links. This makes it the starting point when the system design calls for a single full-width server, accelerator or storage connection.
Use BCM85668 for an x8 path. Its smaller eight-lane package supports one x8 link, two x4 links or four x2 links. It is a candidate for a narrower riser, backplane or storage connection. One BCM85668 cannot retime a full x16 link by itself; a multi-device x16 arrangement would require separate board and interoperability validation.
Both product briefs describe low-latency operation, link training, a 100 MHz reference clock and more than 36 dB of reach extension at 64 GT/s under Broadcom's stated conditions. That figure is not a guaranteed cable length. Check loss, placement, clocking, power, firmware and end-to-end interoperability for the actual host-to-endpoint channel. CXL use also requires support from the rest of the system.
Information to include in an RFQ
Provide the complete manufacturer ordering code, quantity, target delivery date, required x16/x8/x4 link arrangement and the B1G or B2G AC-capacitor option. Ask for availability and the appropriate design documents for the exact part number; do not infer stock or lead time from a related Broadcom device.
Browse our Broadcom PCIe switch category for existing switch selections, or read our PEX89000 PCIe 5.0 switch overview when the requirement is PCIe fan-out rather than link retiming. Send an RFQ for the exact BCM85667 or BCM85668 variant.
