CareerCup

That's not entirely correct, the max value for Xmx is theoritically 2^bitness (32 or 64 bit).
For a 32 bit UNIX based system, you could set up to 3GB as the rest of the process address space needs approximately 1 GB (Total address space on a 32 bit kernel is 4GB). So your answer should mention the value and the reasoning behind coming up with that value.If you have tried practically then it helps as well.

This value can be set by:
run-->regedit
HKEY Local Machine -->Software-->MicroStrategy--->JNI bridge--->Configuration-->Diagnostics-->JVM options--> click HEAP MAX SPACE

THe maximum value you can set depends on how much free RAM space can be made available to the JVM. Ite generally set to 512MB.