Pentium OverDrive - Socket 8

Socket 8

In 1998 the Pentium II OverDrive, part number PODP66X333, was released as an upgrade path for Pentium Pro owners. This upgrade could be used in single and dual processor Socket 8 systems, or in two sockets of quad processor Socket 8 systems with CPU 3 and 4 removed.

Combining the Pentium II Deschutes core in a flip-chip package with a 512 KB full speed L2 cache chip from the Pentium II Xeon into a Socket 8-compatible module resulted in a 300 or 333 MHz processor that could run on a 60 or 66 MHz front side bus. This combination brought together some of the more attractive aspects of the Pentium II and the Pentium II Xeon: MMX support/improved 16-bit performance and full-speed L2 cache, respectively. The later "Dixon" mobile Pentium II core would emulate this combination with its 256 KB of full-speed cache.

In Intel's "Family/Model/Stepping" scheme, the Pentium II OverDrive CPU is family 6, model 3. Though it was based on the Deschutes core, when queried by the CPUID command, it identified as a Klamath Pentium II. As noted in the Pentium II Processor update documentation from Intel, "Please note that although this processor has a CPUID of 163xh, it uses a Pentium II processor CPUID 065xh processor core."

The major customer for the production of these chips was Sandia National Laboratories' ASCI Red supercomputer, which had all 4,510 CPUs upgraded in 1999. After the upgrade the system was once again the world's fastest on the Top500.