Hi,
I've been struggling with this issue for a while. When I download a game through steam or battle.net it cripples my pc but with the origin client in doesn't. I have 250gb samsung 970pro as boot drive, an older crucial 250gb I now use for games and a 3tb WD green HDD. I usually set the clients on the 970 pro and then download the game to crusial ssd. Now, at first I thought the issue might be that somehow the steam client is choking the 970pro. So I set both the client and the game itself on the crusial ssd. Same thing happens. Tried the HDD as well for good measure, same thing. And it's not like my cpu or memory are slacking either. I run a 3600x and 16gb 3200mh ram. During downloads my cpu is at 40-50%. And none of my disks seem go over 10 % usage. But now when I download from the origin client it's the opposite. Now the cpu is at 10% and the disk is at 90-100% and my pc is still working just fine.
It's the weirdest thing ever so I hope somebody here might have a clue to what going on.