O'Reilly logo

The Unabridged Pentium 4 IA32 Processor Genealogy by Bob Colwell, Tom Shanley

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

The Basic Request Types

Request Type 1

General

Request type 1 was introduced in the Pentium® processor and is supported by all subsequent IA32 processors (as well as the later 486 models). When the input value in EAX = 1 (i.e., request type 1), the processor returns the following items of information:

  • Prior to the advent of the Pentium® 4 processor, the information shown in Figure 59-2 on page 1448 is returned in EAX. With the advent of the Pentium® 4 processor, the information shown in Figure 59-3 on page 1448 is returned in EAX. Table 59-2 on page 1449 defines the processor type field values.

    Figure 59-2. CPUID Request Type 1 EAX Content (pre-Pentium® 4)
    Figure 59-3. CPUID Request Type 1 EAX Content (Pentium® 4)
    Table 59-2. Processor Type Field ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required