The !smt extension displays a summary of the simultaneous multithreaded processor information.



Windows 2000


Windows XP and later



Here is an example:

lkd> !smt 
SMT Summary:
   KeActiveProcessors: **------------------------------ (00000003)
        KiIdleSummary: -------------------------------- (00000000)
 No PRCB     Set Master SMT Set                                     IAID
  0 820f4820 Master     **------------------------------ (00000003)  00
  1 87a4d120 820f4820   **------------------------------ (00000003)  01

Maximum cores per physical processor:   2
Maximum logical processors per core:    1

The No column indicates the number of the processor.

The PRCB column indicates the address of the processor control block for the processor. Each logical processor is listed separately.

Each physical processor has exactly one logical processor listed as the Master under the Set Master column.

The SMT Set column lists the processor's simultaneous multithreaded processor set information.

The IAID column lists the initial Advanced Programmable Interrupt Controller identifier (APIC ID). On a true x64 computer, each processor starts with a hard-coded initial APIC ID. This ID value can be retrieved through the CPUID instruction. On certain other computers, the initial APIC ID is not necessarily unique across all processors, so the APIC ID that is accessible through the APIC's memory-mapped input/output (MMIO) space can be modified. This technique enables software to allocate unique APIC IDs for all processors within the computer. Depending on the target computer's processors, the IAID column may show this ID or may be blank.