Use a wifi analyzer to see the least congested channel for both the 2.4GHz and 5GHz band and set your wifi channel there. You can use different names for the 2.4 and 5, and I recommend doing that, as the 5 have much lower range than 2.4, and not all device support the 5.

You means change the chanel that less ppl use will be better is it? Example: if 3 ppl using chanel 1, then change to other chanel that nobody use..

I set it as same ssid. Newer devices are capable of band steering. Meaning if u are close, it'll change to 5 if u are far it'll automatically change to 2.4

Well in any case u can try using same or different and see whatever suits u.

For additional AP i also set it as same ssid but different channel

1 SSID to rule them all
LoL

Yes. That's it. I would recommend Channel 1, 6, or 11, depending on your area, as they are the only channels that does not interfere with one another.

No use.

Every Tom, Dick and Harry in the neighbourhood who knows also use channels 1, 6 and 11.

Use 5Ghz, channel 149, perfecto!

Even worse, routers that defaults to 40Mhz bandwidth.

In most cases, you'll have to compromise for a channel with the lowest signal strength coming from other routers in the area.

I have to agree with the badly-coded firmware. The fact that it takes 5 mins to boot-up is a good indication. (TP-Link says that's normal ) The Asus RT-AC1200G+ uses the same CPU as the C1200 and doesn't seem to have that problem.

The Broadcom BCM47189 @ 900 MHz in the Archer C1200 is quite a respectable processor.

It would be very difficult to max it out even under very heavy loads.

Instantaneous 100% peaks are possible, but not consistently at 100%.

Yeah, the culprit is most probably badly coded firmware.

let' see tplink can flashable to 3rd party firmware to run?

The TP-Link Archer C1200 was only released in Feb 2017.

It is too new to be supported by DD-WRT.

Here is the list of TP-Link supported devices.

http://www.dd-wrt.com/wiki/index.php/Suppo...Devices#TP-Link

It seems someone has done it but no link???

The DD-WRT firmware for the C1200 is not available yet.

See here for the list of TP-Link supported devices.

http://www.dd-wrt.com/wiki/index.php/Suppo...Devices#TP-Link

Really?

Where did he get it from?

Is he talking about the C1200?

I am confused.

No idea, I searched but couldn't find any. Maybe lyt25_1234 can help us.

Lol. If you can't beat em', join em!

All 3 of the Archer C1200 CPU usage now working with lower CPU usage after disabling SPI firewall and USB Sharing. Lazy to check which one is the cause of high CPU load problem. But I don't need any of those feature anyway.

TP-Link Archer C1200 CPU Usage (YouTube)

Best regard.

It would be better if you telnet/ssh into the router and run 'top' command, then sort it by cpu usage by pressing "SHIFT + F", next press 'k' (small letter, not capital letter).
Then we can discover which process causes high cpu usage.

This confirms that the issue is with TP-Link's badly-coded firmware.

For comparison, here is a snapshot of my Huawei WS880 dual-core 800MHz Broadcom processor running Xwrt-Vortex firmware.

There are currently 7 devices connected to the router.

One with LAN cable, three on 2.4GHz and three on 5GHz.

Two of them are torrenting and one is streaming 1080p60fps video, the rest are surfing the web.

The total dual-core processor utilization is only a total of 10%, hardly breaking a sweat.