> how does [100BASE-TX] save power vs [1000BASE-T] running at low throughput?
100BASE-TX uses just two pairs (lanes), one for sending and one for receiving. 1000BASE-T uses all four pairs, for both sending and receiving. Therefore, a 100BASE-TX interface that's only receiving needs to power up one pair. A 1000BASE-T interface needs to power all four pairs all the time.
I recall reading about some extensions that allow switching off some of the pairs some of the time ("Green Ethernet"), but I think that they require support on both sides of the link, and I'm not sure if they are widely deployed.
My only annoyance with "Green Ethernet" things is that often they seem to work poorly.
The dedicated machine I still keep around for Windows things has two onboard 2.5GbE ports. It will apparently sometimes, even with all power saving features turned off, randomly negotiate down to 100 mbit if I leave the machine alone for a bit, and then stay at that speed forever unless I manually reset the link after wondering why transferring large amounts of data is bottlenecking severely.
100 mode saved me once when I really really really needed to have a connection in that moment, but the ethernet cable glued to the wall that I was using had only three out of eight wires even functioning.
According to the technician I spoke with, he could only detect three on their end.
The cable was chewed through by cats, so perhaps it was three just in that moment.
I also appreciate the 10/100 support. I recently needed it for some old voip equipment, and it was shockingly difficult to find an SFP+ module that worked in my 10G switch and supported 100mbps.
Isn’t that only relevant for network topologies that rely heavily on broadcasting to multiple nodes. Eg token ring, WiFi and powerline adapters?
For regular Ethernet, the switch will have a table of which IPs are on which NIC and thus can dynamically send packets at the right transmission protocols supported by those NICs without degrading the service of other NICs.
I’ve seen some vlans hit 1mbit BUM filters, I think we had about 800 users on that one. To saturate a 10m link would require a help of a lot of broadcast traffic.
100m is fine. 10m is fine but I can’t think of anything that negotiates 10m other than maybe WOL (I don’t use it enough to be sure from memory).
If I didn ahve something esoteric it would be on a specialised vlan anyway.
Is that really true? If so, is there a saner way to handle this than upgrade all the things to 10GBE? Like a POE ethernet condom that interfaces with both network and devices at native max speeds without the core network having to degrade?
I'm guessing different mainboards could offer better USB port support for Gen 2 2x2, but right now the Ryzen AI 13" chips at least top out at USB4 / 3.2 Gen 2x1
"Card supports 10Gbit/s and 10/100/1000/2500/5000/10000Mbit/s Ethernet"
Nice to see; some NICs are shedding 10/100 support. Apparently, it's not necessary to do this, even in a low cost device.