Hmm. By default, Win32 processes are limited to 2GB of ram with the other 2GB of physical address space being reserved for kernel mode use. There are several mechanisms for going beyond that.

• There is something referred to as the /3GB switch.

  This is a boot time parameter that allows user space to be extended by a specifiable amount upto the 3GB limit with the consequent reduction in the kernel mode space available. It has restrictions upon the version of the OS and the hardware in use.

• There is a thing called Physical Address Extension (PAE).

  This allows some versions of win32 (probably more expensive ones:), to take advantage of installed memory beyond the 4GB limit.

• And another thing called Address Window Extensions.

  This requires the application to be written to take advantage of addressing beyond the 4GB limit.

However, if your Perl script is bumping it's head upon the normal 2GB limit, it is probably time to consider your options for reducing it's memory requirements. Often that can be a relatively painless process of adjusting your algorithms or substituting less memory hungary data structures.

I won't speculate about your particular problem, but there have been several pretty successful examples of memory reduction here at PM over the last few years.