Will EFT protection on data center switches affect port speed?

Improper selection of EFT protection devices in data center switches can affect high-speed signal quality and lead to port speed degradation. For example, when the capacitance to ground of the signal line is greater than 5pF, a 25% attenuation in the eye diagram height of a 1000Base-T switch may reduce the speed to 100Mbps. Correct selection: For the series ferrite bead on the signal line, use the Etymotic PBZ1608A-102Z0T (1000Ω@100MHz), with a DC resistance of only 0.5Ω and negligible voltage drop; for the parallel TVS, use ultra-low capacitance ESDLC3V3D3B (1.2pF) or ESDLC5V0D8B (0.2pF); in terms of layout, place the TVS on the connector side, 3-5mm away from the PHY chip. Actual testing showed that with a 1.2pF TVS, the gigabit port throughput reached 940Mbps without errors, while with a 47pF ordinary TVS, the throughput dropped to 320Mbps and generated numerous CRC errors.