Intel Pentium III 533B & 600B

The heat has definitely been turned on for chip giant, Intel. With the release of the Athlon processor and, as a result, the loss of the performance throne to AMD, Intel sped up their launch cycles for the last quarter of 1999. Among those changes was the decision to move up the launch of the 133MHz FSB for the GTL+ bus architecture to September 27.

According to the way things should have gone, the September 27^th launch of the 133MHz FSB should have coincided with two events: the release of the Intel 820 chipset with the first official support for the 133MHz FSB, and the release of the first Pentium III processors with 133MHz FSB support. Only one of those two events occurred, because, as you now know, the 820 release has been pushed back due to stability problems. Making it out of the Intel plants in two clock speeds, 533MHz, and 600MHz, what is to distinguish these two processors from the previous Pentium III CPUs that operate at a 100MHz FSB? The 133MHz FSB Pentium III processors will carry the ‘B’ extension to their name. Since the 533MHz Pentium III is the only Pentium III around at that clock speed there doesn’t have to be a distinction there but the Pentium III 600 is now available in two different flavors, the 100MHz FSB version and the 133MHz FSB version, otherwise known as the Pentium III 600B.

So what makes the Pentium III B any different from the previous generation of Pentium III processors? Other than different clock multipliers and a different pin setting to allow motherboards to detect the processors as 133MHz FSB CPUs, there is absolutely no difference between the Pentium III and the Pentium III B.

The real reason for a review on the Pentium III 533/600B is to illustrate the performance improvement (if any) those processors at the 133MHz FSB, offer.

Currently there are three platforms that officially support the 133MHz FSB, the i810E, the Apollo Pro 133, and the newest revision of the Apollo Pro 133 using the 82C694X North Bridge controller. Although we have had i820 samples in house for quite a while, stability issues have kept that chipset from becoming a part of those aforementioned platforms. The i440BX chipset can’t be used as a test bed since the 133MHz FSB, albeit unofficially supported, puts the AGP frequency at ~89MHz, a full 35% above the AGP specification and causes all 3D graphics cards to fail under normal stress conditions. This leaves us with a low end chipset, two VIA chipsets, and an unreleased Intel chipset to test the performance of the 133MHz FSB. So how do we illustrate the performance increase the 133MHz FSB offers with the Pentium III? First, we must understand Intel’s reasoning behind the move to the 133MHz FSB.