I've been having trouble adding more ram to mc. i used to have 5Gb of ram when i start up.But, ever sense i added the variable PATH (the system variable PATH, for using java and eclipse) i am not able to add more then 1Gb of ram. This has been a big issue and have crashed at least 30 time in 1 week or so, just because it doesn't have enough ram to continue. Also this relates to another problem. Not only have i been crashing due to not enough ram, many other random thing i would of never crash of, or never happend, until i added that PATH system variable. like error registering texture, unknown errors, sound system failing and needing reloading (F3 + S if you didn't know, takes a while if you have a slow computer, i don't though) and so on. I really need to use the java PATH system variable due to the fact i am a plugin coder for bukkit (not related to anything of the post at all, just the reason why added the variable) help would be nice, as joining servers is possible, but crashing frequently isn't what i like to do daily. And yes, i know how to add more RAM, it just fails of the JVM not starting up correctly. (JVM = Java Virtual Machine)
Also, you can't allocated more RAM than you have, 15G means 15 gigabytes of RAM, or 5G meaning 5 gigabytes of RAM.
I have 10 GB RAM and I allocated in the minecraft launcher with:
...which allocated 8 of my 10 gigs to minecraft.
You can't allocate more RAM than you have; meaning if you have only 1 GB of ram, your launcher JVM arguments would look like this:
....that should work fine and you should stop getting an error telling you that you don't have enough RAM.
EDIT: Also, you shouldn't need a path. Either you allocated more RAM than you have, or your path is wrong.