REALMEMSIZE System Option: Windows

Specifies the amount of real memory SAS can expect to allocate.

Valid in: configuration file, SAS invocation
Category: System Administration: Memory
Default: 0
Windows specifics: valid values


-REALMEMSIZE n | nK | nM | nG | hexX | MIN | MAX

Required Arguments

n | nK | nM | nG

specifies the amount of memory to reserve in multiples of 1; 1,024 (kilobytes); 1,048,576 (megabytes); and 1,073,741,824 (gigabytes), respectively. The value of n can be a decimal value. For example, a value of 8 specifies 8 bytes, a value of .782k specifies 801 bytes, and a value of 3m specifies 3,145,728 bytes. Under 32-bit operating environments, the largest value that you can specify is 4294967295 (4G–1).


specifies the amount of memory as a hexadecimal value. You must specify the value beginning with a number (0–9), followed by an X. For example, the value 2dx sets the amount of memory to 45 bytes.


specifies a value of 0 that indicates that the memory usage is determined by SAS when SAS starts.


specifies to set the memory size to the largest permissible value.


Some SAS procedures use the REALMEMSIZE option to specify how much virtual memory the procedure can allocate and use without inducing excessive page swapping. By contrast, the MEMSIZE option places a limit on the total amount of virtual memory that SAS dynamically allocates at any time. This virtual memory is supported by a combination of real memory and paging space. The operating environment begins paging when the amount of virtual memory that is required exceeds the real memory that is available. To prevent paging and the associated performance problems, the REALMEMSIZE and MEMSIZE options should be set to a subset of real memory.


The REALMEMSIZE option is similar to the SORTSIZE option. The REALMEMSIZE option affects multiple procedures. The SORTSIZE option affects only the SORT procedure.