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by Jamesits 55 days ago
I don't understand the decisions to use RJ45 copper cable for anything higher than 1GbE, unless

  a) You like small computers and these only comes with RJ45 ports and 0 PCIe slots
  b) You enjoy fighting with super rigid cables, port flaps and hot modules
I upgraded my home to full 10Gbps network at 2018. At that time:

  * 10Gbps SFP+ PCIe NICs (Mellanox CX3 and similar cards) are already dirt cheap ($15 for OCP adapted ones, $50 for native PCIe cards) because datacenters are upgrading to CX5
  * 10KM SM SFP+ modules are already dirt cheap (~$6) because 4G BBU-RRU communication uses these
  * Silent 10Gbps SFP+ switches start appearing (still a little pricey); 10Gbps RJ45 switches are not available anywhere
Those 10KM SM modules will happily run off <20m MM fibers so I just used whatever fiber I have at hand. The price is so cheap that I think the RJ45 upgrade path (2.5G has not been universal, 5G still very far away, 10G is so pricey) looks like a scam.

After 2024:

  * 25G/100G SFP+ PCIe NICs are dirt cheap (~$80 for single port 100G NIC)
  * 100G QSFP28 modules are in acceptable price; 25G SM/CWDM SFP+ modules area already dirt cheap (~$50 for 6-slot CWDM ones) because 5G BBU-RRU communication uses these
  * Silent 100Gbps switches start appearing (you can get 24*25G + 4*100G under 100W; still a little pricey); 100Gbps RJ45 switches are not available anywhere
I already have an experimental 6*25G CWDM fiber connection between my 2 rooms. Given that most of my devices wouldn't need anything higher than 10Gbps, I'm thinking of giving each room a single 100G port, split them into 4 lanes in the room with passive wavelength splitters for different devices, which further reduces cost on switches.
1 comments

Power usage is a good reason to stick with non-SFP ports.

And you can use CAT5e with 10Gbps networks given the run is short enough. I run 2.5Gbps over CAT5e with no issues throughout my house (I don't need that much bandwidth except when downloading Steam games).

10Gbps fibre uses significantly less power than 10Gbps copper ethernet.
I read that parent comment as referring to POE, but am doubting myself after reading yours.

POE is a great reason for rj45.