Retrieves statistics about the global memory utilization.
Returns FALSE on failure, or an array consisting of the following information on success:
loadThe current memory load in percent of physical memory.
unitThis is always 1024, and indicates that the following values are the count of 1024 bytes.
total_physThe amount of total physical memory.
avail_physThe amount of still available physical memory.
total_pagefileThe amount of total pageable memory (physical memory + paging file).
avail_pagefileThe amount of still available pageable memory (physical memory + paging file).
total_virtualThe amount of total virtual memory for a process.
avail_virtualThe amount of still available virtual memory for a process.