Processor Types and Specifications - Upgrading and Repairing PCs - page 94

module (MCM) physical format, which Intel calls a dual-cavity PGA package . Inside the 387-pin
chip carrier are two dies. One contains the actual Pentium Pro processor, and the other contains a
256KB, 512KB, or 1MB L2 cache. (The Pentium Pro with 256KB cache is shown in Figure 3.26 .)
The processor die contains 5.5 million transistors, the 256KB cache die contains 15.5 million
transistors, and the 512KB cache die(s) have 31 million transistors each—for a potential total of
nearly 68 million transistors in a Pentium Pro with 1MB of internal cache! A Pentium Pro with 1MB
cache has two 512KB cache die(s) and a standard P6 processor die (see Figure 3.27 ). The
incorporation of L2 cache is one of the most enduring legacies of the Pentium Pro because this feature
has been incorporated into virtually every Intel and AMD processor built since, with the notable
exception of the original Celeron.
Figure 3.26. Pentium Pro processor with 256KB L2 cache. (The cache is on the left side of the
processor die.) Photograph used by permission of Intel Corporation.
Figure 3.27. Pentium Pro processor with 1MB L2 cache. (The cache is in the center and right
portions of the die.) Photograph used by permission of Intel Corporation.
For more information about the Pentium Pro, see Chapter 3 of Upgrading and Repairing PCs, 19 th
Edition, available in its entirety on the disc packaged with this topic.
Pentium II Processors