Internet Speed Troubleshooting

[armc3j]

Hello.

I'm currently paying for the xfinity 300Mbps data plan, but my computer will only record speeds of 42Mbps (according to fast.com) and 63 Mbps (according to the xfinity speed test). These tests are performed over wifi, with my computer next to the router. The router itself is a NETGEAR Cable Modem Wifi Router Combo C6250, which is capable of speeds up to 300Mbps.

Out in our living room, my internet functions reasonably well. However, when I'm in my room (approx. 30 ft from the router) my internet quality drops immensely--I can barely stream youtube in 720p. I've tried restarting the router, but that hasn't worked so far. Can anyone help? I should be getting better internet speeds considering what I'm paying for, correct?

It's just myself and 2 others using the wifi, so there shouldn't be an issue with overloading the network.

[EG]

For a test, does a computer hardwired directly to the C6250 with an ethernet cable have the same problem ?

With this test, we are trying to isolate this from being either a WiFi-only problem or a problem with the general connection to the Comcast system which would of course affect both. It's a good first step of troubleshooting before we proceed any further.

[armc3j]

When plugged in to the router via ethernet, my computer records wifi download speeds of

180 Mbps (fast.com)

127.3 Mbps (xfinity speed test)

both of these are significantly faster than the original test, which was performed in the same spot (just without ethernet).