Fun With Multigig Ethernet
June 11, 2022
I love the new batch of multigig Ethernet peripherals that allow you to run 2.5 Gbps and 5 Gbps over your existing Cat5e cabling.
Comcast’s modem supports 2.5 Gbps, and I can now tap into the full 1.4 Gbps download capacity over wired Ethernet.
But not all multigig Ethernet devices are created equal!
From my experiments, the best option for switches appears to be the 10/5/2.5 Gbps ones that give you 10 Gbps bandwidth between local devices, and 5 Gbps between switches over Cat5e. I’ve had a really good experience with the TRENDnet TEG-S750.
You can get 2.5 Gbps switches too, but they appear to have much lower internal bandwidth. Since you’re likely to encounter computers that support 10 Gbps in the future because it’s an established standard, it’s probably wiser to just go with 10 Gbps today.
Your options for endpoints are not very encouraging. The best way to connect remains to get a 10 Gbps Thunderbolt or PCI adapter, which you connect to a 10 Gbps switch, which uses a 2.5 or 5 Gbps backhaul.
On my Mac, I use the Sonnet Solo10G, which works flawlessly, but is really expensive.
I have an OWC 10/5/2.5 Thunderbolt3 adapter on order, which costs significantly less than the Sonnet Solo10G. I’ll do more experiments with it when it gets here.
Update: It works great!
My gaming PC comes with a 2.5 Gbps Ethernet connector on the motherboard, and it works great as well.
The story with USB-based adapters is not as rosy. I’ve tried two USB-C Ethernet adapters: a 2.5 Gbps one, and a 5/2.5 Gbps one, both made by TRENDnet. Neither delivered what they promised.
The problem seems to be that USB 3.1 gets bogged down with overhead very quickly, which is especially problematic when you have a barrage of small packets to be serviced. In practical terms, USB 3.1 Ethernet adapters max out at 1.3 Gbps sustained throughput, regardless of Ethernet cable speed.
In summary, here are my findings if you want to upgrade your home networking to multigig Ethernet:
- Buy 10/5/2.5 Gbps switches for best performance and compatibility. It’s worth the extra price.
- Don’t bother with 2.5 Gbps switches unless you’re constrained by budget or space.
- Buy 10/5/2.5 Thunderbolt3 or PCI endpoints.
- Don’t bother buying USB 3.1 dongles that claim to be faster than 1 Gbps. They don’t deliver.