Asus RT-AC66 (Merlin): PS4 downloads using 100% of CPU

[Trembler]

I've run into a problem after getting a PS4.

Whenever the PS4 starts a download (wired) the CPU utilization goes up to 100% and the rest of the network just halts. How can this be when the download is barely pushing 70 Mb/s? I have a 250/20 Mbit/s line

To put things into perspective it is normally around 5-11% with 9 wired clients and 22 wireless, 20% if the download link is saturated.

I am not using the wireless on the Asus as this is handled by an Ubiquiti AC Pro - When the PS4 is on wireless the Asus CPU goes to down to around 50-60%

Any input would be much appreciated

 

[Trembler]

So I borrowed a friends PFSense box: https://www.supermicro.nl/products/system/Mini-ITX/SYS-E200-9B.cfm

This has 8gb of ram and an SSD and even on this router the CPU is using 90% when there is more than 1 download on the PS4 - Does that even make sense?