Maximum possible heap size and maximum recommended heap size (32-bit Java)

http://publib.boulder.ibm.com/infocenter/javasdk/tools/index.jsp?topic=%2Fcom.ibm.java.doc.igaa%2F_1vg00014884d287-11c3fb28dae-7ff6_1001.html

Platform	Additional options	Maximum heap size	Recommended heap size limit	Additional notes
AIX	None	3.25 GB	2.5 GB	Maximum heap size is not required to be, but should ideally be, a multiple of 256 MB
Linux	None	2 GB	1.5 GB
	Hugemem Kernel	3 GB	2.5 GB
Windows	None	1.8 GB	1.5 GB
	/3GB	1.8 GB	1.8 GB