SYSTEM_INFO Structure

Contains information about the current computer system. This includes the architecture and type of the processor, the number of processors in the system, the page size, and other such information.
Syntax

C++
typedef struct _SYSTEM_INFO {
union {
DWORD dwOemId;
struct {
WORD wProcessorArchitecture;
WORD wReserved;
} ;
} ;
DWORD dwPageSize;
LPVOID lpMinimumApplicationAddress;
LPVOID lpMaximumApplicationAddress;
DWORD_PTR dwActiveProcessorMask;
DWORD dwNumberOfProcessors;
DWORD dwProcessorType;
DWORD dwAllocationGranularity;
WORD wProcessorLevel;
WORD wProcessorRevision;
}SYSTEM_INFO;
Members

dwOemId
An obsolete member that is retained for compatibility. Applications should use the wProcessorArchitecture branch of the union.

wProcessorArchitecture
The processor architecture of the installed operating system. This member can be one of the following values.

Value Meaning
PROCESSOR_ARCHITECTURE_AMD64
9
x64 (AMD or Intel)
PROCESSOR_ARCHITECTURE_IA64
6
Intel Itanium Processor Family (IPF)
PROCESSOR_ARCHITECTURE_INTEL
0
x86
PROCESSOR_ARCHITECTURE_UNKNOWN
0xffff
Unknown architecture.

wReserved
This member is reserved for future use.

dwPageSize
The page size and the granularity of page protection and commitment. This is the page size used by the VirtualAlloc function.

lpMinimumApplicationAddress
A pointer to the lowest memory address accessible to applications and dynamic-link libraries (DLLs).

lpMaximumApplicationAddress
A pointer to the highest memory address accessible to applications and DLLs.

dwActiveProcessorMask
A mask representing the set of processors configured into the system. Bit 0 is processor 0; bit 31 is processor 31.

dwNumberOfProcessors
The number of physical processors in the system. To retrieve the number of logical processors, use the GetLogicalProcessorInformation function.

dwProcessorType
An obsolete member that is retained for compatibility. Use the wProcessorArchitecture, wProcessorLevel, and wProcessorRevision members to determine the type of processor.

Name Value
PROCESSOR_INTEL_386
386
PROCESSOR_INTEL_486
486
PROCESSOR_INTEL_PENTIUM
586
PROCESSOR_INTEL_IA64
2200
PROCESSOR_AMD_X8664
8664

dwAllocationGranularity
The granularity for the starting address at which virtual memory can be allocated. For more information, see VirtualAlloc.

wProcessorLevel
The architecture-dependent processor level. It should be used only for display purposes. To determine the feature set of a processor, use the IsProcessorFeaturePresent function.

If wProcessorArchitecture is PROCESSOR_ARCHITECTURE_INTEL, wProcessorLevel is defined by the CPU vendor.

If wProcessorArchitecture is PROCESSOR_ARCHITECTURE_IA64, wProcessorLevel is set to 1.

wProcessorRevision
The architecture-dependent processor revision. The following table shows how the revision value is assembled for each type of processor architecture.

Processor Value
Intel Pentium, Cyrix, or NextGen 586 The high byte is the model and the low byte is the stepping. For example, if the value is xxyy, the model number and stepping can be displayed as follows:
Model xx, Stepping yy
Intel 80386 or 80486 A value of the form xxyz.
If xx is equal to 0xFF, y – 0xA is the model number, and z is the stepping identifier.
If xx is not equal to 0xFF, xx + ‘A’ is the stepping letter and yz is the minor stepping.

Examples

For an example, see Getting Hardware Information.

Requirements

Minimum supported client Windows 2000 Professional
Minimum supported server Windows 2000 Server
Header Winbase.h (include Windows.h)

GetSystemInfo Function

Retrieves information about the current system.
To retrieve accurate information for an application running on WOW64, call the GetNativeSystemInfo function.

Syntax

C++
void WINAPI GetSystemInfo(
__out LPSYSTEM_INFO lpSystemInfo
);
Parameters

lpSystemInfo [out]
A pointer to a SYSTEM_INFO structure that receives the information.

Return Value

This function does not return a value.

Examples

For an example, see Getting Hardware Information.

Requirements

Minimum supported client Windows 2000 Professional
Minimum supported server Windows 2000 Server
Header Winbase.h (include Windows.h)
Library Kernel32.lib
DLL Kernel32.dll