Comment by Galanwe
5 hours ago
10G DACs are no cheaper than cat6, which is perfectly fine for 10G at most practical distances. Considering the target audience of these cards it seems pretty obvious to me that letting users "just buy a cat 6 cable" is miles more reasonable than having them buy a transceiver or DAC.
As for allowing to switch to fiber, that just seems orthogonal again to what these USB NICs are for, not to mention the SFP+ itself is probably more expensive than the NIC shown here...
DACs are very cheap (second hand and AliExpress) and they never use much W. If both machines are near each other though (which a DAC cable implies) and both run Linux and both support Thunderbolt, you might be better off with a direct ethernet over TB connection. Whether macOS supports such, I don't know.
The other side will then also need a low power NIC (of which fiber and DAC over SFP+ are less power hungry). What this article doesn't mention, is that there are also a lot of PCIe NICs on the market which aren't power hungry (RTL8127), as well as RTL8261C for switches/routers.
I've seen low power RTL NICs with SFP+ on it, too (example: [1]). With SFP+, you'll have a lot more versatility. DAC and SFP+ fiber are very cheap, btw. Especially second hand they go for virtually nothing. I have 10 SFP+ fiber lying around here doing nothing which I got for a few EUR each.
For me as European with high energy prices and solar energy gotten the beat next year (in NL), this is all very interesting.
There's a couple of good reasons why to opt for fiber in the home. You keep the energy between the different groups separated which can help. I also find fiber very easy to get through walls, allowing me to have multiple fiber connections through walls (currently I use 1x fiber + 1x ethernet for PoE possibilities from fusebox).
With all above being said, AQC100S is low power and does not get very hot. You can get these with SFP+ and PCIe/TB. They've been available for a while.
[1] https://nl.aliexpress.com/item/1005011733192115.html (no vouching for, just first hit on search)