My recalbox panel show that my raspberry has only 250mb of ram while my model (Pi3 A+) has 512mb. Do recalbox split with gpu all that ram?If yes, there are ways without overclocking to make the ps1 "havier" games running smoothly?

All ps1 games I have tested run quite smooth but I found a little fps difference with more "recent" games. For example Crash Bandicoot 1 run smoother than Crash Bandicoot 3 cause the graphic is better. Are there tricks to let the raspberry do the best for the heavier games. For example adding more ram to gpu is the way?