I'd bet for the null hypothesis: the memory behaviour changes would hold if the core count was kept constant and only the VM's memory size was adjusted.
I'd bet for the null hypothesis: the memory behaviour changes would hold if the core count was kept constant and only the VM's memory size was adjusted.
Agreed. This is the OS adapting to available memory.
Similarly if you started with 4GB and there was 900MB available for user apps, I expect you could launch apps that consume 1500MB just fine; the OS is leaving enough to launch anything, and making use of unused memory for cache/etc.