ICX7450 with ICX7400-4X10GF 4-port 40G Module Clients are only connecting at
5G, not 10G?

Question

We have an ICX7750 with 48 port 10G module. All clients connect at 10G no problem.

The same clients - Mac High Sierra & Windows 10 - when connected to our ICX7450 with ICX7400 module, only achieve 5G speeds.

The module is recognised ok by the switch, and the ports are running at 10G Full. Auto neg is not available on these ports - I think they only run at 10G.

unknown · Answer

SFP+ modules regardless of platform or vendor usually do not support auto negotiation.I am not certain what you have for the Macintosh systems, but unless they are servers, I cannot see that 10 Gbps would even be helpful.  If they are servers, the issue is most certainly those computers vs the ICX 7750 switch.

unknown · Answer

It is the internal, hidden ethernet cabling in our building (inherited).I ran a direct cable test to the switch (which I should have done immediately) and 10G is achieved.That is a real shame. It will be costly for us to upgrade our cabling. We will live with 5G for now.