java memory allocation fails (eclipse xp dell)

Question

I have a problem at some customer pc's (new Dell PCs)

windows XP Professional SP3, 4GB RAM

if I try to start eclipse using -Xms256m -Xmx1024m than it fails reducing to -Xms256m -Xmx768m then it works

any idea what could be wrong ?

on my own machine I'm using OSX with Parallels VM running the same XP Prof SP3 then inside this XP I can easy allocate -Xmx1024m or more

Answer 1

You're probably using SUN's Java VM. This VM needs to allocate its memory in a continuous block. In your case, a 768 MB large block would be free, but not a 1024MB large block. Solution would be to switch to XP 64 bit, which has a larger address room an thus is able to supply such a large block using higher virtual addresses.

See also http://stackoverflow.com/questions/171205/java-maximum-memory-on-windows-xp