CPUCOUNT= System Option

Specifies the number of processors that the thread-enabled applications should assume will be available for concurrent processing.
Valid in: Configuration file, SAS invocation, OPTIONS statement, SAS System Options window
Category: System administration: Performance
PROC OPTIONS GROUP= PERFORMANCE
Default: Under Windows and z/OS, the default is ACTUAL. Under UNIX, the default is either ACTUAL or 4 for systems that have more than four processors.
Interaction: If the THREADS system option is set to NOTHREADS, the CPUCOUNT= option has no effect.
Note: This option cannot be restricted by a site administrator. For more information, see Restricted Options.
Syntax
Details
Comparisons
See Also

Syntax

CPUCOUNT= 1 - 1024 | ACTUAL

Syntax Description

1-1024
is the number of CPUs that SAS will assume are available for use by thread-enabled applications.
Tips:The value is typically set to the actual number of CPUs available to the current process by your configuration.

Setting CPUCOUNT= to a number greater than the actual number of available CPUs might result in reduced overall performance of SAS.

ACTUAL
returns the number of physical processors that are associated with the operating system where SAS is executing. If the operating system is executing in a partition, the value of the CPUCOUNT system is the number of physical processors that are associated with the operating system in that partition.
Tips:This number can be less than the physical number of CPUs if the SAS process has been restricted by system administration tools.

Setting CPUCOUNT= to ACTUAL at any time causes the option to be reset to the number of physical processors that are associated with the operating system at that time. If the operating system is executing in a partition, the value of the CPUCOUNT system is the number of physical processors that are associated with the operating system in that partition.

If your system supports Simultaneous Multi-Threading (SMT), hyperthreading, or Chip Multi-Threading (CMT), the value of the CPUCOUNT= option represents the number of such threads on the system.

Details

Certain procedures have been modified to take advantage of multiple CPUs by threading the procedure processing. The Base SAS engine also uses threading to create an index. The CPUCOUNT= option provides the information that is needed to make decisions about the allocation of threads.
Changing the value of CPUCOUNT= affects the degree of parallelism each thread-enabled process attempts to achieve. Setting CPUCOUNT to a number greater than the actual number of available CPUs might result in reduced overall performance of SAS.

Comparisons

When the related system option THREADS is in effect, threading will be active where available. The value of the CPUCOUNT= option affects the performance of THREADS by suggesting how many system CPUs are available for use by thread-enabled SAS procedures.

See Also

Support for Parallel Processing
System Options:
THREADS System Option
UTILLOC= System Option
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