Intel 64 and IA-32 Architectures Software Developers Manual Volume 2A, Instruction Set Reference, A-M

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INSTRUCTION SET REFERENCE, A-M
INPUT EAX = 4: Returns Deterministic Cache Parameters for Each Level
When CPUID executes with EAX set to 4 and ECX contains an index value, the
processor returns encoded data that describe a set of deterministic cache parame-
ters (for the cache level associated with the input in ECX). Valid index values start
from 0.
Software can enumerate the deterministic cache parameters for each level of the
cache hierarchy starting with an index value of 0, until the parameters report the
value associated with the cache type field is 0. The architecturally defined fields
reported by deterministic cache parameters are documented in Table 3-12.
The CPUID leaf 4 also reports information about maximum number of cores in a
physical package. This information is constant for all valid index values. Software can
query maximum number of cores per physical package by executing CPUID with
EAX=4 and ECX=0.
INPUT EAX = 5: Returns MONITOR and MWAIT Features
When CPUID executes with EAX set to 5, the processor returns information about
features available to MONITOR/MWAIT instructions. The MONITOR instruction is used
for address-range monitoring in conjunction with MWAIT instruction. The MWAIT
instruction optionally provides additional extensions for advanced power manage-
ment. See Table 3-12.
INPUT EAX = 6: Returns Thermal and Power Management Features
When CPUID executes with EAX set to 6, the processor returns information about
thermal and power management features. See Table 3-12.
INPUT EAX = 10: Returns Architectural Performance Monitoring Features
When CPUID executes with EAX set to 10, the processor returns information about
support for architectural performance monitoring capabilities. Architectural perfor-
mance monitoring is supported if the version ID (see Table 3-12) is greater than
Pn 0. See Table 3-12.
For each version of architectural performance monitoring capability, software must
enumerate this leaf to discover the programming facilities and the architectural
performance events available in the processor. The details are described in Chapter
18, “Debugging and Performance Monitoring,” in the Intel® 64 and IA-32 Architec-
tures Software Developer’s Manual, Volume 3B.
METHODS FOR RETURNING BRANDING INFORMATION
Use the following techniques to access branding information:
1. Processor brand string method; this method also returns the processor’s
maximum operating frequency
2. Processor brand index; this method uses a software supplied brand string table.