The Meaning of Life, the Universe, and Everything.
I know Java is a memory hog, but this looks like something else. It's not just using a few hundred MBs more, it uses factors more!
When I configure -Xmx512m, it uses 1800MiB
When I configure -Xmx1024m, it uses over 4100MiB.
JVisualVM reports that it's using less than configured (same as value in F3 screen), but Process Explorer says otherwise.
Clearly the growth in memory is directly proportional to the Heap space, although I can't fathom why.
I've searched for this problem but 99% of what I find are tutorials on how to increase memory so, sorry if this has been asked before.
The problem is that, if I run it with 1024m, Windows starts randomly and silently killing off applications, starting with Minecraft, Firefox and Process Explorer(!). It doesn't give me a prior warning anymore like it used to (which in itself is strange). When I run it with 512m, and Forge enabled, Minecraft won't even start.