Coppermine Overclocking - turning a 650 into 890 MHz machine

With the high price of processors at the top end of the spectrum, combined with the ability to run processors faster than their rated speed, why pay extra for performance when you can enhance the performance of your existing processor. Before you read any further, it should be noted that the topics discussed in this epinion WILL VOID the warranty of your processor. It is possible to destroy hardware while you are attempting to do what I am going to discuss in this epinion. Should you destroy your processor while trying to overclock, neither I, nor Epinions can be held responsible. Use the following advise at your own risk.

In addition to Advance Transfer Cache (See my Pentium III Explained review), one major advance in the Coppermine processor line was the introduction of .18 micron silicon wafers. This results in two major differences. One is a lower cost for the manufacturer. They are able to get more chips off the same silicon wafer, the other is lower heat disappation. (Note the reduciton in core voltage for the Coppermine vs Katmai processors, from 2.0v to 1.6 (FC-PGA) or 1.65 (Slot 1) ) Although the processors do run cooler than their Katmai coutnerparts, you still need to improve the stock cooling provided with the Coppermine processor. The heat sink is simply not big enough, and the fan is too weak. The best aftermarket cooler available is the Alpha P3125. They can be obtained for about $50 online.

In order install an Alpha P3125 heat sink, we need to remove the existing heat sink and fan. This is where we begin to void warranties. Removing the fan and heatsink will instantly void your warranty. It is also possible for you to destroy your processor while removing the case. Fortunately case removal is very simple.

Looking at the case, the process of removing the case looks formidable. Fortunately, looks can be deceiving. ( There is a decent online tutorial at www.3dfxcool.com. Use the search engine and look for removing case ) The first step is to remove the stock fan. This doesn't require any tools. Simply squeeze on the ends of the fan and remove the cover by hand. This will leave you with the heat sink exposed. You will notice that there are four pins holding the heat sink to the processor. These are one way insertable pins that Intel uses. The Intel recommend way to remove the pins is to use a special jig and drill them out. Without the special jig, you risk destroying your processor.

Fortunately, there is an easier method to remove the pins. All you need is a screw from the back of your PC case, a screw driver, and a flat, hard, stable surface. On the side of the case cover opposite the fan are the back sides of the four pins holding the heat sink in place. The end of a case screw will fit in the hole for the insert pin. Place the screw on a table end up, align to one of the four studs, and press hard. The heat sink pin will pop up. Repeat this process 3 times and you can remove the stock heatsink.

For the service of anyone not familiar with the Alpha P3125, I will do a review in the next few days, but simply put, it is the best, non-peltier after market cooler available. Until then, trust me this is the heat sink and fan you want to attach to your processor. The P3125 is designed to attach to a Pentium III and comes with all of the supporting hardware needed. The case removal process described earlier only takes about 10 minutes, and reattachment of a new heat sink and fan is an similarly easy process. Simply spread a good THIN layer of thermal grease (proviced with P3125) on the top of the processor. This will eliminate air pockets that can trap heat. After applying thermal grease, position the processor on the heat sink by aligning the holes. Make sure that the heat sink is in EVEN contact with the processor while attaching the four screws used to attach the P3125.

This probably seems like a lot o hassle for people who have never overclocked. You may wonder why bother. The reason is simple. Money. The cost on 3/17/2000 for a Pentium III 650 is $316 (plus 50 for an Alpha P3125). I am currently running my Pentium III 650 at 890MHz. As of 3/17/2000, there are no Pentium III 900's on Priceline, so I will use a Pentium III 850 instead. A Pentium III 850 currently goes for $960. Therefore, for about an hour of time, and a little effore, you can save $600 and have a better performing machine.

Note: This review covers my experience with a Pentium III 650 and concentrates on cooling. To understand the basics of overclockability (bus speeds and frequency multipliers) see my epinion called Hidden Bargain, Overclocking the Pentium III. For a good motherboard for overclocking, see my review on the ABIT BE6 Rev. 2