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This comment is an offtopic rant about the bane of 2.5gbit nics. A discussion about how awesome and cheap 25gbit nics are (on iOS devices no less!) seems as goo

This comment is an offtopic rant about the bane of 2.5gbit nics. A discussion about how awesome and cheap 25gbit nics are (on iOS devices no less!) seems as good a place as any to bring it up. 2.5gbit nics are a boondoggle. They must contain the same 10gbit capable transceivers as any other n-base-t transceiver (because that's how they work) yet they are sold with the 5gbit and 10gbit rates disabled. Ostensably this is to limit power draw (and heat) but in most applications they are used those things aren't actually much of an issue. What will it take to get non-nerfed 10gbit nics as standard offerings on consumer hardware? 2.5Gbit is simply not fast enough to move data in and out of modern systems with modern storage. It's a twisted joke that network connectivity is so shit on systems that otherwise bend over backwards to advertise how many thunderbolt and 10gbit usb ports they have.

crest 2y ago
The advantage to 2.5Gb/s is that you can run it over reasonable lengths of existing crappy cable jobs about as well as 1Gb/s Ethernet without angry customers yelling blaming you because it doesn't work. sigh
justsomehnguy 2y ago
> to limit power draw (and heat) Yes. Did you ever been in an actual DC and handled 10G-T cables and ports? They are hot, even in the DC with HVAC running below 20°C. And there is only one type of the systems which can easily accept that amount amount of heat - the desktop *ATX systems, for which you can just go and buy a 10G PCI-E card. For everything else the amount of heat is too much.
- justinclift 2y ago
  DACs don't seem to have that problem.
  - justsomehnguy 2y ago
    DAC definitely has that problem too. One cable in an ideal condition probably wouldn't be that hot, but as soon as something is not ideal it would get hot. Also you are just throwing everything here now, DAC is totally not "we can have 10G for free". As others has said, the main benefit of 1G/2.5G is what it uses the same twisted pair => 8p8c connector. 10G DAC is SFP+. This alone prevents the mass adoption in the consumer sector - too much friction for Regular Joe.
    - justinclift 2y ago
      > Also you are just throwing everything here now ... ?
- gorkish 2y ago
  So yeah I do deal with 10GBaseT sometimes. IMO its mostly an economies-of-scale issue. 802.3an is up against some physical limits, but there have been many improvements even since the first products hit the market. The newer PHYs used in the newest multirate SFP+/BaseT transceivers, for instance are not nearly as hot as the old 1st gen products. More users = more incentive to fix the problem. I wonder if it might be possible via software/firmware hack to unlock the 5G/10G rates on any existing 2.5G chipset?

crest 2y ago

The advantage to 2.5Gb/s is that you can run it over reasonable lengths of existing crappy cable jobs about as well as 1Gb/s Ethernet without angry customers yelling blaming you because it doesn't work. sigh

justsomehnguy 2y ago

> to limit power draw (and heat) Yes. Did you ever been in an actual DC and handled 10G-T cables and ports? They are hot, even in the DC with HVAC running below 20°C. And there is only one type of the systems which can easily accept that amount amount of heat - the desktop *ATX systems, for which you can just go and buy a 10G PCI-E card. For everything else the amount of heat is too much.

justinclift 2y ago
DACs don't seem to have that problem.
- justsomehnguy 2y ago
  DAC definitely has that problem too. One cable in an ideal condition probably wouldn't be that hot, but as soon as something is not ideal it would get hot. Also you are just throwing everything here now, DAC is totally not "we can have 10G for free". As others has said, the main benefit of 1G/2.5G is what it uses the same twisted pair => 8p8c connector. 10G DAC is SFP+. This alone prevents the mass adoption in the consumer sector - too much friction for Regular Joe.
  - justinclift 2y ago
    > Also you are just throwing everything here now ... ?
gorkish 2y ago
So yeah I do deal with 10GBaseT sometimes. IMO its mostly an economies-of-scale issue. 802.3an is up against some physical limits, but there have been many improvements even since the first products hit the market. The newer PHYs used in the newest multirate SFP+/BaseT transceivers, for instance are not nearly as hot as the old 1st gen products. More users = more incentive to fix the problem. I wonder if it might be possible via software/firmware hack to unlock the 5G/10G rates on any existing 2.5G chipset?