Why is the Xmx java argument set so low in the default eclipse.ini in the Mac OS X distribution of Eclipse?

Why is the Xmx java argument set so low in the default eclipse.ini file in the Mac OS X distribution of Eclipse? I often find Eclipse to be very sluggish prior to increasing the Xmx argument manually. By default, it was set to 384M. Modern IDEs should be expected to take up around 2G开发者_StackOverflowB of memory.

One of the reasons: "Changing the heap size does impact the amount of memory used by the process, which results in less memory being available for other processes." https://bugs.eclipse.org/bugs/show_bug.cgi?id=265525#c16

Also see comment #43 on that page for potential problems high Xmx value may cause.