R8500 Slow Download but OK Upload



I'm trying to troubleshoot something. Of course, multiple things have changed over a couple days so it's hard for me to pinpoint the culprit.


I installed an R8500 and I did a speedtest and got ~175 Mbps down and ~22 Mbps up. This is close to the provisioned speed for Comcast Extreme 150.


I am now getting ~15-20 Mbps down but still ~20-22 Mbps up. I find this odd that upload is not affected.


What is odd, is that I had this same problem with my prior router, an R7000. I even had 2 of these, had the same problem come up on both. I got the new modem (above) and was running fine.


Like I said, there are lots of things that all happened, but I'm posting here in case anyone has any troubleshooting ideas. One of the things that changed, was upgrading firmware. It is now at V1.0.2.54_1.0.56. I didn't write down what it came with.

Model: R8500|Nighthawk X8 Tri-Band AC5300 WiFi Router
Message 1 of 3

Re: R8500 Slow Download but OK Upload

Quick update.


I did a factory reset just prior to posting the above. It didn't seem to fix the problem. However, I've done nothing else but waited a few minutes after that reset, created the above post, and re-set up my WiFi SSIDs/passwords. But then I tested again, and speedtest is now FINE! 179 Mbps down / 24 Mbps up. Tested multiple times now.


This problem has been going on All day, so I don't think it's coincedental.


It seems that the ONLY thing that fixed this was the factory reset. So, I'm still thinking, there is something in the settings that causes this problem.


HOWEVER: I then tested via 2.4 GHz wifi. I'm not familiar with what speeds to expect, but I don't think this is right: I got 5.5 Mbps down and 24 Mbps up. So, AGAIN, it's this weird slow down only problem.


I turned off WMM and QOS based on something else I read. Then I was getting about 17.5 Mbps both up and down on 2.4 GHz WiFi. Maybe this is it?


Is there a known setting that would cause this weird problem?

Model: R8500|Nighthawk X8 Tri-Band AC5300 WiFi Router
Message 2 of 3

Re: R8500 Slow Download but OK Upload

QoS most likely the culprit. WMM should be enabled for the wireless clients.

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