Unfortunately, the Athlon X2’s fiasco in power consumption tests is accompanied by pretty sad overclocking results, too. Of course, the only one to blame is the old 65nm Kuma core that has already proven overclocking-unfriendly before.
This time we checked the overclocking potential of Athlon X2 7000 series trying to achieve maximum clock frequency on a system with the top solution in the lineup – Athlon XP 7850. Overclocking experiments were done on the same platform as the performance tests. We used Scythe Mugen CPU cooler.
However, even with a relatively powerful cooler and processor core voltage increased from 1.3V to 1.475V we couldn’t get the system to work stably at anything past 3.25GHz.
Therefore, the fact that Athlon X2 7850 and 7750 processors belong to the Black Edition series and therefore have an unlocked clock frequency multiplier is a very weak compensation. In reality, these processors can only be overclocked slightly, by no more than 20-25%.
Intel Pentium, however, is a totally different story. These processors are based on 45nm Wolfdale core that is currently one of the most overclocking friendly choices. As a result, by raising the core voltage from 1.25V to 1.45V we could easily push the Pentium E5400 frequency to 4.0GHz with Scythe Mugen CPU cooler.
I would like to stress that not very high USB frequency supported by Pentium processors in the nominal mode helps the overclocking success. Since dual-core Intel CPUs have a locked clock multiplier, we can only play around with the FSB frequency during overclocking. But even in our case when the frequency of our overclocked processor increased by almost 50%, the FSB speed only reached 297MHz. I am sure that any mainboard can do it, even inexpensive platforms on cut-down chipsets like Intel P43, for instance.
So, Pentium overclocking is just as easy as Athlon X2 Black Edition overclocking. However, the results are much more impressive in the former case: against Pentium’s background we can barely consider Athlon X2 as an option for computer enthusiasts.