Channel Insertion Loss

NVIDIA BlueField-3 Networking Platform User Guide

Channel insertion loss is the signal power loss resulting from a device's insertion in a transmission line or optical fiber and is usually expressed in decibels (dB).

The following table describes the NVIDIA® BlueField®-3 channel insertion loss budget for PCIe Gen 5.0 architecture (32 GT/s).

The total PCIe channel insertion loss approved by PCI-SIG Gen5.0 spec is 36dB @16GHz.

The total BlueField-3 DPU board insertion loss of the PCIe lanes (PCORE1) routed to the Cabline CA-II Plus is 6dB (@16GHz).

The Passive Socket Direct PCIe Auxiliary Card Loss is 1.5dB (@16Ghz).

The Cabline CA-II Plus harness loss at 16GHz:

Harness Length

Channel Loss at Gen 5.0

15cm

3.8dB

35cm

7.6dB

55cm

11.4dB

The above is measured data; it is recommended to add 0.5dB margins for your system (some loss variations are possible).

The Cabline CA-II Plus harnesses loss = 0.24dB/cm for Gen 5.0.

The above loss includes the Cabline CA-II Plus harnesses and connectors on both sides.

The PCI-SIG Gen5 SPEC also defines the total loss for AIC (bump to GF) to be 9.5dB @16Ghz.

Please note that the BlueField-3 AIC, together with a 15cm Cabline CA-II Plus harnesses and the Passive PCIe Auxiliary Card loss is 10.3dB, which is approved by NVIDIA.

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