Introduction
More Overclocking!
Hot on the heels of our 600E overclocking article, we "procured" an FC-PGA 650E for overclocking purposes. We were curious to see what benefits the higher multiplier present on the 650E allows. For instance, in many cases CPU overclocking with the BX chipset is frequently held back by the AGP card, which often has trouble beyond 124MHz front side bus speeds. In this case, the 650E would achieve a higher clock speed than a 550E or 600E.
We've discussed the basics of the various Pentium III processors in our 600E overclocking article, so we won't rehash them here. Instead we'll elaborate on a few things we didn't discuss in the original article. If you aren't familiar with the letter designations given to the Pentium III, have questions about identifying your processor, or want more background information in general we suggest you start there.
FC-PGA versus S.E.C.C.2
A few of the emails we've received related to Pentium III overclocking asked which processor is better for overclocking: those with the FC-PGA packaging or those based on S.E.C.C.2. In practice, there's little difference between the FC-PGA and S.E.C.C.2 packages in relation to overclocking. The main difference at this point is cost. FC-PGA CPU's typically sell for less than their S.E.C.C.2 counterpart. In some cases by a significant amount less.
In direct contrast to this is the small selection of motherboards that support the FC-PGA format. Over the coming months this will change, but to date Tyan and MSI are the only well-known motherboard manufacturers with FC-PGA products available on the market.
Intel plans to shift all manufacturing to the FC-PGA format. By the end of this year expect FC-PGA to be widely available in terms of processors and motherboards.
Retail vs. OEM
Another frequent topic is retail versus OEM. Overall, you won't have a greater chance of overclocking with a retail boxed processor in comparison to a plain OEM unit. However, when Intel shifts from one process to another (say for example 0.25-micron to 0.18-micron) slower processors based on this new process can be extremely good overclockers. This didn't occur in the case of the "Coppermine" Pentium III, as they're all based on a 0.18-micron core, the most recent example was a group of retail and OEM Pentium II 266's and 300's that achieved clock speeds in excess of 400MHz quite easily.
All is not lost however. Just recently, Intel began production of a new core stepping (cB0) for the Pentium III processor. With the design improvements made in this new stepping, Intel was able to break the 1GHz mark last month. Many in the overclocking community are hoping that the same enhancements that allows this new stepping to achieve such high clock speeds will make overclocking even easier for slower processors that are also based on this stepping.