dont waste a dime on that laptop, its not worth any upgrade, only good at school work and access on remote place and browse the net.
ps.
there is a thumb rule ram = same in swapfile, problem here is how fast is write on disk sametime, slow harddisk then you make more a bottleneck and all can feel slow/ laggy, so ½ or 1/4 could actual be better, whats the point in huge cache if disk cant keep up and it feel like long wait time ( almost afrozen system with red glowing harddisk led that never stop )
and automatic could be best but it has also be seen that static 4/8/16 can be better so it wont resize all the time.
( again because of this, dont have multi apps running you only get a bottleneck, that pc is outdate ) and many could tell you that, but why should they reply, then already one person point it out.
go ask steam hardware group, get help there, dont forget we have to write nicely here. most ppl will have said something very hard at our equipment, dont get me wrong hornesty is better then someone tell you that pc is anygood other then maybe school work, or faulty finding laptop i use to get around to other people and help them ( working and test pc. ) that is what your pc can do.
you can use alot app taht can optimized that pc, but it wont help in running games.
ccleaner ( junk and windows registration repare )
use advance system care free ( check pc )
iobit driver booster ( check for newest drivers )
this will feel like a boost, but it will not change anything requirements from games is way to high.