
CPU Identification Algorithms
3
21062E/0—June 1997
AMD K86 Family BIOS and Software Tools Developers Guide
Preliminary Information
2
CPU Identification
Algorithms
The CPUID instruction provides complete information about
the processor (vendor, type, name, etc.) and its capabilities
(features). After detecting the processor and its capabilities,
software can be accurately tuned to the system for maximum
performance and benefit to users. For example, game software
can test the performance level available from a particular
processor by detecting the type or speed of the processor. If the
performance level is high enough, the software can enable
additional capabilities or more advanced algorithms. Another
example involves testing whether the processor supports
MMX technology. If the software finds this feature present
when it checks the feature bits, it can utilize these more
powerful instructions for better performance on new
multimedia software.
For more detailed information refer to the
AMD Processor
Recognition Application Note
, order# #20734, located at
http://www.amd.com
Tables 1 and 2 outline the family codes and model codes for the
AMD K86 processors. Table 1 shows the CPU speed, the
‘P-Rating’, and the recommended BIOS boot-string associated
with each AMD-K5 processor.
Table 2 shows the recommended BIOS boot-string for the
AMD-K6 MMX enhanced processor. This recommended
boot-string is ‘AMD-K6(tm)/XXX’. The value for XXX is