I recently got the FW Ethernet Expansion Card and was wondering about what driver to use with Windows.
Windows 11 comes with a default driver 11.1.621.2021, but that one offers no power saving options at all and leads to a draw of 0.23W idling without any network plugged in (and ~0.7W with an active 2.5G connection).
Using the newest driver from Realtek directly (1188.8.131.520 from the Win11 11.13.0420 package) has a bunch of power saving options, all of which are disabled by default also leading to the same 0.23W of power draw.
With “Idle Power Saving” enabled and “idle power down restriction” set to disabled (defaults to not as long as user is present) power consumption can go down to 0.18W and after a few seconds the whole USB connection is put to sleep leading to a power consumption of 0.04W idle. The same numbers are reached under Linux / Fedora 38 after ensuring USB power saving is allowed.
The other power saving options in the Windows driver only influence how low the consumption can get when a connection is actually active (I saw ~0.32W when idling on a 2.5G connection, ~0.7W when receiving at full bandwidth).
But using an older driver that I had on some of my devices, due to Dell docks and monitors that also use Realtek USB LAN adapters I can get far lower idle consumption still:
1156.9.823.2022 (from Dell Realtek USB GB Ethernet driver 1153.9.823.2022 A28, for example from the Dell WD19TB downloads. Realtek themselves seems to not have an archive of older drivers):
The idle power saving is enabled by default, also some of the other energy efficiency measures, Leading to an idle (no network plugged in) draw of only 0.005W, the same draw I measure with the DP and HDMI expansion cards (gen2 and gen3 respectively), when USB is put to sleep.
So it actually seems, that Realtek has a giant regression in how deep their controllers can sleep when not connected in any of the 2023 drivers (Dell also has the A29 driver package, only claiming it adds support for new devices, which uses newer 2023 drivers that already have the regression).
Note: I am measuring this with a TC66C, so the absolute numbers might not be reliable, although I would expect the magnitudes of difference to remain true.
@Framework: Might be worth to have an Knowledge Base advisory which driver you recommend / tested with, in case there are known bugs with the older, most power saving driver or any of the energy efficiency options. Both seemed to work for me, but it would be totally possible that this driver has been superseeded to work around hardware flaws in the chipset.
On the other hand, I tested all my USB-C adapters (DP, HDMI, 2.5G ethernet) and the current generation of FW expansion cards has by FAR the lowest power consumptions. And in USB-C hubs, the ethernet modules are often not put to sleep by default, keeping the whole thing wide awake. So it might also be that basically nobody else cares about power consumption like we do here with the expansion cards and Realtek just does not know how they screwed up their drivers…
I have now realized, that the official FW driver package for 12th gen already included some Realtek Ethernet drivers. I did not even think to look there, because I installed them before I believe the ethernet adapter was even available for order and I would not want to install that driver package now, because I assume it would override all the much newer drivers that came out since than. And I had other devices with Realtek USB Ethernet controllers that shipped much newer drivers than those in the meantime.
But I unpacked the ethernet driver installer from it and installed that manually. It seems this is the Windows 10 driver from Realtek, version 10.53.20.520 (older than the Dell driver I would recommend for now, I really do not understand how Realtek numbers their drivers…).
This driver does not have the option to block idling when the user is present, like all the newer Win11 drivers have, but the crucial “Idle Power Saving” option is off by default, leading to a power draw of 0.23W on default. After enabling Idle Power Down, I see 0.1W idling. All the other options do not change this. So, power consumption wise, the official driver seems worse than newer drivers, even worse then the newest Realtek drivers and also does not set the impactful Idling option.