Pentium II

In 1997, Intel produced the Pentium II, which was really just an enhanced Pentium Pro with speeds ranging from 233 MHz to 450 MHz. The Pentium II had a 64-bit data bus, a 36-bit address bus (64GB of RAM), and 64-bit registers and supports features such as MMX.

The Pentium II increased the amount of L1 cache that was integrated into the CPU to 32K, as opposed to 16K. The 32K of L1 cache was still divided into two equal channels: one 16K channel for data and one 16K channel for application code.

Intel packaged the Pentium II in the Single Edge Contact (SEC), sometimes also referred to as the Single Edge Contact Connector (SECC), that fits into Slot 1 on the motherboard. The SEC is a module enclosed in a casing or shell with two chips inside, one chip being the processor and the other chip being the 512K of L2 cache.

Another enhancement that accompanied the Pentium II was Single Instruction Multiple Data (SIMD). To visualize how SIMD works, imagine five toddlers in a playroom, and that these toddlers are at the entertaining age of two - the age, of course, when the toddlers are preparing for their teen years by answering "no" to everything you say. You walk into the playroom and see that the five toddlers have found your box of darts and are throwing them at the walls. You are faced with a choice: You can either walk around to each child and explain why throwing darts at your walls is not a good idea (which means you will have to explain the same thing five different times), or you can have a good scream at the top of your lungs, which means that all the children will stop immediately and listen. SIMD works on the same basic principle. With SIMD, the processor gives the instruction to multiple processes at once - instead of having to give the same instruction multiple times. Thus, the processor saves time and creates a much more efficient way to work with information.

Celeron

The Pentium II processor performs very well, and with all that cache memory, it should! Unfortunately, that performance comes with a price. If you are not willing to pay that price, Intel has created a chip for you: the Celeron chip!

The Celeron chip is nothing more than a less-expensive version of the Pentium II processor with the built-in L2 cache either removed entirely or reduced. The first-generation Celeron chip was code-named the Covington; it has no L2 cache memory on it. The second-generation Celeron was codenamed the Mendocino, and it contains 128K of L2 cache. Although this version of the Celeron does have L2 cache, it is dramatically reduced the Pentium II's 512K so that it can be sold at a lower price.

The original Celeron shipped in an SEC package but also had a version that was packaged as a PGA.