But were the ports USB2 or USB3? If they both were USB3, maybe there is a setting in BIOS to change them to work in USB2-mode or use USB2-hub in the middle.
At least on Windows side years ago, when I flashed my Xperia 10, I used my old i5-2500K powered computer and had zero problems, when using USB2-port.
Then I’m out of ideas what could have caused your tries to fail, but I’m still pretty confident your old CPU wasn’t the reason. If you ever need to flash your phone (again) in the future and run into any problems, don’t hesitate to post on the forum, so smarter people than me can help you troubleshoot and guide you through the issues.
I did everything according to Sony’s instructions. The flashing process always crashed at some point. While searching for answers to the problems, I discovered that I am certainly not the only one having problems.
That is strange based on my limited experience.
Building the images prior to flashing was always the hurdle for me and where I crashed.
But flashing did work always on my 20 years old Dell machine running Debian.
Yesterday in other thread about flashing problems I saw a possible fix, that I remember seeing before, but had completely forgot it, so I couldn’t suggest it in my earlier replies.
You should test @direc85’s trick for turning off the autosuspend for USB and see, if the flashing works after that: