You don’t need old hardware to verify the speed differences. If you just take a browser in i3wm on bare arch Linux install that will be faster than in windows10 on the same machine. At least snappier. It’s just significantly lower overheads in Linux because you can tailor to your needs and remove all bloat. Also windows GUI is just more taxing on the system compared to Linux so that is going to be better at rendering something like a simple browser. Linux is slightly faster in some benchmarks(like geek bench) but overall the differences are minor when comparing apples to apples. It’s things GUI related where Linux has the edge in performance and some of the recent games have for some reason performed better on Linux than Windows according to an LTT video which is due to some real interest and development in Linux gaming.