SAS System Options under Windows

MEMBLKSZ System Option: Windows

Specifies the memory block size for memory-based libraries for Windows operating environments.

Default:	16 MB
Valid in:	configuration file, SAS invocation
Category:	System administration: Memory
PROC OPTIONS GROUP	MEMORY
Windows specifics:	all

Syntax
Details
See Also

Syntax

-MEMBLKSZ n | nK | nM |nG | nT | hexX

n | nK | nM | nG | nT: specifies the memory block size in multiples of 1; 1,024 (kilobytes); 1,048,576 (megabytes); 1,073,741,824 (gigabytes); and 1,099,511,627,776 (terabytes), respectively. You can specify decimal values for the number of kilobytes, megabytes, gigabytes, or terabytes. 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.
hexX: specifies the memory block size 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 memory block size to 45 bytes.

Details

Beginning with Windows 2000, multiple processes can be run simultaneously in memory. The value of the MEMBLKSZ system option is the amount of memory that is initially allocated. Additional memory can be allocated in the same memory allocation size that is specified in the MEMBLKSZ option, up to the amount of memory that is specified in the MEMMAXSZ option. For example, if MEMBLKSZ is 2M, additional memory can be allocated in 2M blocks.

When memory-based libraries are using extended memory, this value is also used to determine the amount of the process address space that is used to access the extended memory.

Note: Specifying a value that is too large could adversely affect performance.

Specifying a value that is too large could adversely affect overall system performance. Try different values for the MEMBLKSZ option to determine the value that gives the best system performance.
If you are using extended memory in 32-bit environments, then specifying a value that is too large could adversely affect SAS performance. A smaller value might be optimal. A good starting point is 64K; however, try different values for the MEMBLKSZ option to determine the value that gives the best SAS performance.