9/10 OutOfMemoryExceptions are caused by 1 of 2 things:
Your VM has run out of heap space, default heap size is 64mb
Your VM has run out of permSpace
As Eclipse based products get larger, the memory requirements go up. MyEclipse is no exception here. The fastest way to work around this issue and also provide some additional boost in performance, we suggest the following command line or ini file arguments:
In the past it was sufficient to merely use the -Xmx512m setting, but we have noticed increasingly so with larger Eclipse-based products that running out of permSpace can occur and give OutOfMemoryExceptions as well, which is why we are now suggesting users increase that setting too.
On Windows and Linux it is fairly straight forward to update your shortcut or startup script/launcher/shortcut respectively to include these arguments. On Mac it’s a little more confusing. For details on how to find the locations of the ini files, look at this FAQ.