Question Why is my 2.4GHz less than 10 mbps when 5GHz WiFi is faster?


Aug 15, 2018
About a month ago, we were told to upgrade to the Xfinity XB6 Gateway from the XB3 model due to our decrease in speed and intermittent internet disconnection. As soon as we replaced it with the new XB6 Gateway, there was a sudden increase in speed and "less" intermittent disconnection.

To cut to the chase, by our third Comcast technician, he was excellent, he was able to check the line from the mainline to the cable box and that checks, the cable box to the modem, that checks, and replacing all of our cables from the cable box to the TV, amplified our signal, replace the male plugs for each cable by splicing and replacing them, "jumpstart" our signal from the TV room to the cable box, (TV and gateway serves two different cable).

It turns out it was our old coax cable that runs from the cable box to the modem in which we had not replaced for more than 5+ years. After that was replaced, I noticed a huge difference in our speed test. He said we were able to get signal going to all of our TV's including our gateway.

Now fast forward to present day, we have been happy with our internet connection. No internet disconnection or slow down in our internet speed. But I have noticed something and that is the fact that our 5GHz WiFi is fast with by doubled or tripled of the speed on just about any device (which is what we want). But when I check on both my wireless desktop/laptop, tablets, and smartphones, they were all getting less than 10mbps on the 2.4GHz.

We are paying for 400mbps and when we connect our office desktop to the ethernet cable, we get 450+ mbps, which is excellent. But not so excellent on wireless devices. Why is that? How do I fix the solution? Should I get a new modem/router (aka gateway)? My IT coworkers definitely recommend getting a third party router.
Agree it does sound like the XB6 Gateway's 2.4Ghz is not as robust as the old router.

One thing I would try, disable the 2.4 completely on the XB6 then take the old router and setup as an AP using 2.4 only, and see how that goes. That is, if you still have the old router, and if it supports AP mode.