SYSTEM_PROCESSOR_SPEED_INFORMATION

The SYSTEM_PROCESSOR_SPEED_INFORMATION structure may be what a successful call to ZwQuerySystemInformation or NtQuerySystemInformation would produce in its output buffer when given the information class SystemProcessorSpeedInformation (0x2B) in versions 3.51 to 4.0. Earlier versions reject this information class as invalid and so do these. Yet Microsoft is known to have defined the information class as SystemPowerInformation in versions 3.51 and 4.0 before version 5.0 redefined it as SystemLegacyDriverInformation.

Documentation Status

The SYSTEM_PROCESSOR_SPEED_INFORMATION structure is not documented. It is known only from type information in early import libraries: GDISRVL.LIB from the Device Driver Kit (DDK) for Windows NT 3.51 and SHELL32.LIB from the DDK for Windows NT 4.0.

Layout

The SYSTEM_PROCESSOR_SPEED_INFORMATION is 0x10 bytes.

ULONG MaximumProcessorSpeed;

ULONG CurrentAvailableSpeed;

ULONG ConfiguredSpeedLimit;

UCHAR PowerLimit;

UCHAR ThermalLimit;

UCHAR TurboLimit;