What is the fastest Linux for a slower computer?
Do not think too much, I spent last couple days testing every freaking combination, install Mint with Xfce, if it is still slow, change desktop to LXDE, those two will work fast even on 15 years old PC, and still very customizable to give them good appearances. This combo is best for noobs.
Make sure that you have a working GPU drivers, that affects very much the performance, even on Xfce. Also note that some environments will play faster than others depending on their compatibility with hardware, so what I mentioned here is not absolutely right. Mint seems to has best hardware support as I …