You could run 5 on that desktop, but you can forget about PiP and will have to run the background windows at absolute minimum, with a very low maxbkfps.

I'd suggest like, maxfps set to 25 and maxbkfps set to like, 5. Also, run it from two directories. Your main from one and alts from another. Then you should be able to run it. It's edging it though, a single core CPU will likely have trouble with this.