Question Video playback lags when downloading at high speeds

[KapJ1coH]

When I am downloading anything at high speed(100-200 Mbps and plus) on steam or other sources, my pc lags. It's not severe, but it causes some inconveniences. I am on wired connection.

Is it normal or there is a way to fix it? Thank you
My setup: Ryzen 7 2700
Asrock x470 master/sli
16gb of ram oc @3400
1080ti
Samsung 500gb pcie ssd
4tb hdd

here is a pic of my task manager

 

[rgd1101]

downloading to the hdd or ssd?

 

[KapJ1coH]

downloading to the hdd or ssd?

Just tried to do it on both separately and it lags in both cases.

 

[rgd1101]

on the task manger change the seq to cpu. what using most of the cpu resource?

 

[KapJ1coH]

on the task manger change the seq to cpu. what using most of the cpu resource?

There is nothing else running. The progs on screenshot are using around 14% together