Not really useful but I get different USB transfer speeds depending on which pc I use. Maybe just make sure you use a usb 3.0 port and make sure it is a usb 3.0 port not just coloured blue. No idea why they are different.

Mainboard model?

Cpu model?

You try changing the clock speeds and voltage manually?

In the mainboards memory qvl list do they state that they tested 4 sticks of your ram?

Technically they can recover anything that isn’t overwritten.