Intel released Pentium II Xeon in June 1998. This is an Intel 6th generation CPU, since it is based on the same architecture used by Pentium Pro.

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Figure 1: Pentium II Xeon processor.

The main difference between Pentium II Xeon and Pentium II is the clock rate on which the L2 memory cache is accessed. While Pentium II Xeon accesses its L2 memory cache using its internal clock rate (e.g., 400 MHz on a 400 MHz Pentium II Xeon), Pentium II accesses its L2 memory cache at half its internal clock rate (e.g., 200 MHz on a 400 MHz Pentium II).

The main technical features of Pentium II Xeon are:

• 16 KB instruction L1 memory cache and 16 KB data L1 memory cache.
• 512 KB, 1 MB or 2 MB L2 memory cache accessed at the same internal clock rate as the CPU.
• 100 MHz external bus.
• Access to up 64 GB RAM memory.
• Symmetric multiprocessing (SMP) up to four CPUs (models with 2 MB L2 cache allowed SMP up to eight CPUs).
• The CPU was installed in a cartridge called SECC (Single Edge Contact Cartridge) and connected to the motherboard through a 330-contact connector called slot 2.
• Based on “Deschutes” core (the same used by Pentium II processors with 100 MHz external bus) and manufactured with 0.25 µm technology, had 7.5 million transistors and used an area of 203 mm2.

Pentium II Xeon used a Pentium II-like slot, but it was incompatible, since it had 330 contacts (Pentium II slot had 220 contacts). This means that we couldn’t install a Pentium II Xeon on a Pentium II motherboard and vice-versa.

In the table below you see all Pentium II Xeon models that were released. TDP stands for Thermal Design Power and indicates the CPU maximum thermal dissipation, i.e., the CPU cooler must be able to dissipate at least this amount of heat.