Highlight of the Program: Overclocking Pentium 4 2.4C

Although we successfully overclocked a Pentium 4 3.0GHz to 3.6GHz using only air-cooling, we were not that satisfied. This processor is quite expensive and its overclocking is not so rewarding as that of low-end models. So, let’s go to the grass-roots: the slowest model of the Pentium 4 family with the 800MHz bus.

Let me introduce to you the actual hero of this review: Intel Pentium 4 2.4C processor. It is not just an ordinary Pentium 4 (the letter C after the frequency is not a slip of the tongue or typo), as it boasts significant innovations:

• Pentium 4 2.4C is intended for work with 800MHz bus. It means that it requires mainboards supporting 200MHz FSB. Such mainboards are those based on the new i875 and i865 chipsets and also – overclocker mainboards based on the old and time-tested i845PE. Thus, Pentium 4 2.4C has a fixed multiplier = 12x.
• Pentium 4 2.4C supports Hyper-Threading, which once was available only in top-end Pentium 4 CPUs. As you know, Hyper-Threading refers to a virtual multiprocessor system. One physical CPU is recognized by the system as two logical CPUs: it helps to load the processor’s computational units to the full and, as a result, to achieve a certain performance gain.
• By launching new processors supporting 800MHz bus, Intel announced its new approach to the CPU voltage formation. The company won’t set a fixed voltage, but will suggest a range of voltages. During the actual production stage all processors are divided into four classes. Each class has a certain voltage from 1.475 to 1.55V, depending on the die quality. Of course, models with the minimal core voltage are most interesting for overclockers as they have the highest speed-up potential. However, there is no marking on the processor telling its voltage, so you cannot know the voltage until you install the CPU into the mainboard.
• The last feature of Pentium 4 2.4C is the use of the new D1 core stepping, coming down from the top-end Pentium 4 processors. This stepping has F29h CPUID and is going to ensure good overclockability.

In fact, Pentium 4 2.4 with the C1 core stepping used to be good for overclocking, too. But there is something wrong about them now, as the last pieces produced do not please us with their overclocking potential any more. Still, Pentium 4 2.4C overclocking is a much more exciting procedure. Even if the 2.4C loses to the 2.4 in the frequency growth, it will beat it up in performance (Hyper-Threading and the 800MHz bus will do the job!).

But let’s turn from the theoretical talk to real life. This is our CPU:

It is an off-the-shelf Pentium 4 2.4C with 800MHz bus, D1 core stepping and SL6WF S-Spec. All available Pentium 4 2.4C processors have this S-Spec. I was unlucky with the Vcore once again. Our participant had the maximum possible Vcore: 1.55V. Still, the above-tested Pentium 4 3.0 had high Vcore, too, but did quite well at overclocking. A few words about the price: I bought Pentium 4 2.4C in an ordinary shop for about $180. I guess such pricing will make this CPU popular among overclockers.