Edit: at risk of preemptively saying “solved” - disabling the QoS on the router bumped the desktop browser speedtest from the ~600 up to >950Mbps.

My internet plan with my ISP is for 1000 Mbps. This is far more than I need almost always, but it is what they say I am paying for. However, I can’t get any speed tests to read more than ~650 Mbps, which is around about what my old package was.

My router itself has a speedtest functionality and that is what I’m getting off of that. As I’m writing this post, I did a speedtest on my wired-in desktop and got ~590Mbps on speedtest.net.

One thought I had was that maybe the ethernet cables themselves are the limit. All of them say ‘cat5e’ (actually, just checked and the modem-to-router is cat6), though, which should be 1000Mbps, yea? I swapped out the cable from the modem to the router once and got the same speed with the new ethernet cable.

Maybe the router is just too weak? Well, I used iperf3 between two desktops that are both hardwired in and I got ~940 “Mbits/sec”. Unless I’m messing up the unit conversion (which I certainly am annoyed by the difference between “megabytes per second” and “megabits per second”), that is the 1000Mbps that I’d expect to max out the ethernet cables. So, since those two machines are going through the router, it doesn’t seem that the router is the bottleneck for my speed to the great outdoors.

The modem? The modem’s specsheet says it can do 2.5Gbps (well, actually I assume there is a funny typo - it says “10/100/1000/2500 Gbps RJ-45 port”, but I don’t think it is doing 2.5 terrabytes/bits per second). The little led on the modem is lit up the color for “an ethernet device is connected at 2500 Mbps”.

So, should I start hassling my ISP about my missing 350 Mbps? Is there some other obvious thing I should test before I hassle them? I certainly don’t want them to say “have you turned it off and on again”? (once I wrote that, I did go and unplug the modem and router, stand around for 30 seconds, and then plug in the modem and then the router. after I did that, I got one speedtest from the router at 820Mbps, and then the next two tests are back to ~550).

Edit: I do not have fiber, I have a coax cable coming into the house. The person trying to sell me fiber said “your current internet is shared with the neighbors”.