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Comment by GeertJohan | Hacker News Reader

A Framework expansion card was also announced this week. https://frame.work/nl/en/products/wisdpi-10g-ethernet-expans...

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That link notes:

"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.

Low-cost devices are exactly where 10/100 is still widely used. On PCs, it's a common power-saving mode.

For those of us who don’t know, how does it save power vs a 1gbe running at low throughput?

> 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.

100M also needs much less signal processing, and at lower speed, than 1G.

10M is even simpler, to the point that even a fast MCU can bit-bang it.

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.

I assume it is for wake-on-LAN. This of course requires the NIC being powered on while the system is sleeping. Lower bandwidth mode = less power draw.

TVs too.

And PoE security cams.

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.

Don’t we need at least four for 100 Mbps?

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.

The connection was overall unreliable, so I guess it must have been four, just not all of the time.

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.

Ah, the old Cat-3 cable. Been there.

There is two wire ethernet that supports 100. It isn't common, but automotive is starting to use it.

3 pairs probably. But then again you only need 2.

Lots of industrial sensors and devices only do 4 wire 100BASE-TX so if there's no fallback to that it would be a paperweight in those situations.

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.

100 is needed for embedded stuff, it'd render a lot of devices unusable (wiznet chips are popular and are 100 only). That'd suck.

IKEA smart home hub is also 100mbit.

Low cost? The link mentions no price, only a "notify me" button as far as I can see. Does it show a(n estimated) price point for you somewhere?

Low cost, as in not data center/server grade hardware.

$99 when I look at the entry in https://frame.work/marketplace/expansion-cards

There are plenty of embedded chips which only provide RMII. No RGMII or alternatives.

That hasn't been true on switched networks in probably 20 years or so.

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.

10m is extended reach copper, you can do about triple the range of 100m with approximately the same transceiver analog prowess.

We have switches now, hubs just don't exist anymore. Switches are not affected by some devices having a lower speed.

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?

> Is that really true?

It's not, cf. sibling posts. The GP probably learned networking in the 80ies~90ies when it was true, but those times are long gone.

(unless you're talking wifi.)

That is complete nonsense and not how switched networks work.

The author only got 7Gbps with a Framework 13 and a 10G adapter from the same brand (WisdPi).

If this is the same adapter in a different housing, will it also be limited to 7Gbps?

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

A Framework SFP+ or SFP28 expansion would be sweet.

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