FS N8550-64C / N8560-64C (Broadcom Tomahawk 2)

The FS N8550-64C and N8560-64C are 1RU bare-metal switches built on the Broadcom BCM56970 (Tomahawk 2) ASIC, targeting dense 100G spine/fabric deployments.

Field Value
ASIC Broadcom BCM56970 (Tomahawk 2)
Ports 64x 100G QSFP28
Switching Capacity 6.4 Tbps
Total Buffer 42 MB
Architecture Unified shared memory (on-chip SRAM)
TX Queues 8 per port

Models

Model Notes
N8550-64C First-generation platform
N8560-64C Second-generation platform (same ASIC, updated hardware design)

Buffer Architecture

Tomahawk 2 (BCM56970) introduced a 42 MB unified shared buffer — a significant improvement over the original Tomahawk's four separate 4 MB pipeline slices. The entire 42 MB pool is accessible to all 64 ports simultaneously, which eliminates the "stranded buffer" problem of the first-generation Tomahawk.

The Tomahawk 2 represented Broadcom's first unification of the Tomahawk buffer architecture, enabling better microburst absorption across the full port complement. This architecture was carried forward and expanded in Tomahawk 3 (64 MB) and Tomahawk 4 (~113 MB).

References

See Also