This might be your solution.
https://answers.microsoft.com/en-us/windows/forum/all/converting-a-microsoft-storage-space-device-back/bf265cf1-9f14-41d5-b6e2-ec4ecf18c09e#:~:text=Storage Spaces helps protect your,virtual drives called storage spaces.
i remember that in earlier versions of w10 the superfetch(sysmain) service was the culprit for this behavior when i had a pc with just a hdd.
it is safe to disable this service to test if disabling it improves performance.
At my workplace we use PRTG from paessler to monitor anything from power state to temps to component failures to resource usage.
It is not ''cheap'' if you surpass 100 sensors after the 30 day trail but depending the size of the farm it might be an option.
do you have any router/managed switch between the isp's router and you and your brothers pc that has Qos enabled?
seems highly unlikely but that is the first thing that jumps to mind
i use a loadtime accelerator mod from nexus https://www.nexusmods.com/fallout4/mods/10283/?tab=description
This mod works well for me but like the creator says it themselfs experiences may vary
i had to fix it myself with flawless widescreen a long wile ago and some modding as far as i remember.
Give this lil bit a read http://www.wsgf.org/dr/dark-souls-prepare-die-edition/en
i use a tp-link uh700 myself for over a year, only issue i had with it initially wasthat the usb cable is only 3 feet, easy to solve with a good usb 3 cable extender