Heap size
The default maximum heap size is half of the physical memory up to a physical memory size of 192 MB. Otherwise, one-fourth of the physical memory up to a physical memory size of 1 GB.
For example, if your machine has 128 MB of physical memory, then the maximum heap size is 64 MB. A greater than or equal to 1 GB of physical memory results in a maximum heap size of 256 MB.
If the maximum heap size is not enough for the client, then you can specify an increased maximum heap size. To do this, use -Xmx in the Java Arguments field in .
For example, -Xmx512m.