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RT-N66U High CPU usage & low speeds?

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tarottots

New Around Here
Hello all,

I recently got 200/20 service from Comcast installed at my house, only to find that I was not getting nearly the speeds I should be. Over WiFi, I'm only getting about 105/20 instead of the full 200/20 I should be. Connected directly to my modem (SB6183), I get the full speeds. When my speeds hit 105 down, my CPU usage is at 100%.

NAT acceleration is on and working, QOS and per-IP traffic monitoring are both disabled.

As far as I could tell, this is not normal for this router. Is there something I'm missing, or do I just need to get a new router?

I'm on AsusWRT-Merlin 380.61. I know it's not the latest, and I'll upgrade it soon, but I can't imagine not being on the absolute latest firmware would cause something like this.

Thank you!
 
What about Parental Controls and URL blocking? Any of those are ON and being used?
 
I'd try a Factory Reset before doing any drastic changes.

Also, you may try John's fork. I just ran some 30-second iperf3 tests from between my Nexus 9 and my RT-N66U (well, technically the server was another wired PC). From the perspective of the Nexus 9 I got 113Mbit transfer and 168Mbit receive, so your 105Mbit does seem slow but not alarmingly slow.

You might also try overclocking but be careful.
 
Over WiFi, I'm only getting about 105/20 instead of the full 200/20 I should be.
What do you get wired through the router? When I had Comcast 105/20 and a RT-N66U I easily got those speeds wired but didn't have a fast enough wireless device to test wireless speeds.

When my speeds hit 105 down, my CPU usage is at 100%.
Is this on wifi? One thing I've noticed with my AC68U (1000 Mhz dual core vs 600 Mhz single core on N66U) is that when running wireless speedtest cpu1 hits around 50% and cpu2 around 30%. This is with NAT acceleration on and CTF enabled. Wired speed test only hit the cpu1 and cpu2 is around zero. Since your 66U is a single core unit that one core is doing double duty when testing speeds on wifi. Perhaps that is part of the issue.
 
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