I want to increase my fps in Minecraft (I play with 10fps) if I increase the RAM the game crashes?
That depends on the PC.
I would recommend installing Optifine. That increases the performance a bit.
Is this already available for 1.15.1?
As an alternative to adding RAM, I can recommend it if you play around with the graphics settings. If you e.g. Put your visibility down, deactivate shadows and switch off or screw down a few more things, should your FPS have already improved.
I'm not sure about that.
I do not think so. But I didn't look it up. Just google it afterwards, if you don't find anything on the official site, it's probably not there yet.
Also on the settings
