RT-AC87U 100% CPU when downloading full speed

[Pizzy09]

Hi There,
I saw that there are many post around there with a similar problem, but I tried all the solutions inside them without success.

I have an RT-AC87U since 4 years, always used Merlin firmware (actually I just installed today 384.13_3). Recently, I upgraded my 100Mb/s connection with a 1Gb FTTH.
Unfortunately I've noticed that when I download something at the maximum speed (or also during a speedtest) the CPU goes to 100% (sometimes both cores, dunno if it's a bug or not).
I have NAT Acceleration enabled (Auto), SPT disabled, SMB, QoS, VPN server and other stuff like that disabled.

I also tried to downgrade to the original firmware with a factory reset (reset button and also WPS method).

But, if I use my ISP modem/router I can reach the full speed.
There's something else that I can do to improve a little bit the performance?

During the download I opened a top in a SSH shell and i noticed that the top 2 processes are:

But, is it normal, isn't it?

Thanks a lot.

 

[ColinTaylor]

I have NAT Acceleration enabled (Auto)....

Check the actual status at Tools > System Information > HW acceleration

I also tried to downgrade to the original firmware with a factory reset (reset button and also WPS method).

That doesn't change the firmware. All it does is reset the current firmware to its default values.

 

[Pizzy09]

Check the actual status at Tools > System Information > HW acceleration


That doesn't change the firmware. All it does is reset the current firmware to its default values.

It is:
HW acceleration Enabled (CTF only)

 

[doczenith1]

With my old 68U I was able to get 940 Mbps with CTF enabled and one core of the cpu would be at 100% so I would think the 87U would be similar. Is your WAN connection PPPoE? Seems like I've heard of issues with that type of connection on fast ISP connections.