from Hacker News

Xfinity XB3 hardware mod: Disable WiFi and save 2 watts

by p1mrx on 3/30/25, 8:52 PM with 43 comments

  • by wpm on 3/31/25, 4:42 AM

    Every ISP should be required upon request to provide the necessary hardware to provide a single IP address on a single copper cable. If some dumb bozo wants to get the ISP deluxe package of gateway/router/DNS sniffer/shit-tier WiFi AP all rolled into one box, fine. The opt out should be as simple as “I have my own equipment, I understand that any support call with you will stop after a public IP is found to be working on premise, now get the hell out of my way thank you”
  • by easton on 3/30/25, 11:49 PM

    I’d note that (outside of Comcast possibly being mad at you breaking the modem), sometimes they push a bad update and you need to reset the modem, and last time I did that I needed to step through the initial setup on the WiFi network before activating bridge mode. So if the wifi hardware is broken you might need to jump through hoops to get through that setup (or swap the modem).
  • by rasz on 3/31/25, 12:29 AM

    In 2014 Liberty Global decided to offer UPC Wifi Free - free roaming wifi on all cable modems they manage. Your own modem would advertise HotSpot and share your own cable connection. In theory you could opt out, in practice when I tried it just meant removing my login credentials while my box still shared and disabling Wifi locally would bring it back after a while. Thankfully Cisco EPC3925 uses BCM43225 mpcie Wifi card and unplugging it removes all mentions of wireless functionality from Setup, problem solved.
  • by don-code on 3/30/25, 11:37 PM

    While I doubt they'd find it - the SOP for issues with these modems must just be to replace them with a new one - something tells me Comcast wouldn't look kindly on physically modifying rental equipment.
  • by johnklos on 3/31/25, 12:40 AM

    It amazes me that devices with Intel Puma chipsets are still sold new and are still in use in 2025. That's another story, though.

    The number of wifi networks that're running around us has gotten so crazy that it's no wonder we all need wifi-6 to even get reasonable speeds. I'm the kind of person who goes around and disables wifi absolutely everywhere possible, so this is good to know, but what'd be even better is if devices stopped running wifi networks behind our backs. Sigh.

  • by metaphor on 3/31/25, 12:47 AM

    Uhhh, sanity check: If you lived in a state like Hawaii where the cost of residential electricity approaches outrageous territory (i.e. ~$0.50/kWh), then you'd be hard pressed to save $1 per month trimming -2.4W nominal consumption with this hack.

    Perhaps I'm just naive, but this struck me as the buried lede:

    > ...but even in bridge mode, the gateway broadcasts several hidden SSIDs with no option to disable the radios.

  • by quailfarmer on 3/31/25, 3:38 AM

    Yes, this is great! They gave me a similar model under the same deal, and it had a fan that would ramp up and down all day and night.