Possible to move the tmp directory of Eclipse?

May have found a way by setting a property called java.io.tmpdir in eclipse.ini. Seems to have changed where most of the read/write activity happens during build at least. For example:

-vmargs
-Xms128m
-Xmx1024m
-XX:MaxPermSize=256M
-Djava.io.tmpdir=E:\tmp

Not sure if it have to be after the -vmargs thing or not, but this seems to work anyways.