Many 10GbE DACs can be hacked to run 25GbE, which is something I had to figure out after realizing that it’s not just plug and play as it was with twisted pair cables coming from 1Gb to 2.5Gb…

https://kohlschuetter.github.io/blog/posts/2026/03/22/unlock...

Thanks! That's very useful, I might have to do the same soon.

Thank you! I had to stop digging at some point, but honestly I can't wait for someone to port Doom to a ONU.

Forgot about ONU ! Now I need to look into what an ONU can do, and what one can run on it...

Thank you! I hope you all have trusted vendors, and no-one gets bent over by the sudden flood of cheap SFP28 cables :-)

I was going from SFP+ to SFP28. Not sure about SFP to SFP28. But with that EEPROM change you could also try going from SFP to SFP+, just use different bandwidth values.

You could also try resoldering new/thicker Twinax wires to old SFP connectors and update the EEPROM. My soldering skills apparently aren't that great. If yours are or you have plenty of old connectors you should give that a try.

Thanks!

AUI: So that's what that port next to the BNC connector on the 3COM 3C509B was for! We've come a long way.

Very timely post!

How does this compare to https://github.com/tianocore/edk2-libc and https://libc.llvm.org/uefi/index.html, for example?

The new low-power Realtek chipsets will definitely push 10 GbE forward because the chipset won't be much more expensive to integrate and run than the 2.5Gbps packages.

It all comes down to performance per Watt, the availability of cheap switching gear, and the actual utility in an office / home environment.

For 10 Gbps, cabling can be an issue. Existing "RJ45"-style Cat 6 cables could still work, but maybe not all of them.

Higher speeds will most likely demand a switch to fiber (for anything longer than a few meters) or Twinax DAC (for inter-device connects). Since Wifi already provides higher speeds, one may be inclined to upgrade just for that (because at some point, Wireless becomes Wired, too).

That change comes with the complexity of running new cabling, fiber splicing, worrying about different connectors (SFP+, SFP28, SFP56, QSFP28, ...), incompatible transceiver certifications, vendor lock-in, etc. Not a problem in the datacenter, but try to explain this to a layman.

Lastly, without a faster pipe to the Internet, what can you do other than NAS and AI? The computers will still get faster chips but most folks won't be able to make use of the bandwidth because they're still stuck on 1Gbps Internet or less.

But that will change. Swiss Init7 has shown that 25GBps Internet at home is not only feasible but also affordable, and China seems to be adding lots of 10G, and fiber in general.

Fun times ahead.

But why is the gear progressing so very slowly? Why a 25 year gap between reasonable power 1Gbps and 10Gbps?

And while not every cat6 will do 10, it would still be worth a shot, and devices aren't using 5 instead they're using even less.

Not to mention that cat8 will happily do 40Gbps as long as you can get from your switch to your end devices in 30 meters.

Perhaps because internet speeds have been under 1gbps most places until recently and the average person doesn't care about file transfers over LAN.

For reference, I'm seeing pings from my Mac to my Linux boxes (Lenovo Tiny5) at well under 1ms, not much worse than between them directly. But yeah, your mileage may vary.

Be sure to test this adapter on iPad Pro, just for kicks (yes it works!)

Although I managed to panic the kernel a couple of times without the extra heatsinks on...

This 100GbE card is an OCP 2.0 type 2 adapter, which will _probably_ not work with the PX PCB since that NIC has two of these mezzanine connectors, and PX only one.

What also may not work are Dell rNDC cards. They look like they have OCP 2.0 type 1 connectors, but may not quite fit (please correct me if I'm wrong). They do however have a nice cooling solution, which could be retrofitted to one of the OCP 2.0 cards.

I've also ordered a Chelsio T6225-OCP cards out of curiosity. These should fit in the PX adapter but require a 3rd-party driver on macOS (which then supports jumbo frames, etc.)

What also fits physically is a Broadcom BCM957304M3040C, but there are no drivers on macOS, and I couldn't get the firmware updated on Linux either.

That’s a good point to note! I think the stacking height would matter, but in theory the single connector is still 8x pcie and should link without the upper 8x lanes connected.

Spec for reference, I’m not 100% sure. https://docs.nvidia.com/nvidia-connectx-5-ethernet-adapter-c...