AMD processors based on 45 nm cores can usually be overclocked to 3.7-3.9 GHz with air cooling. And this is normally true not only for quad-core but also for dual- and triple-core processors from Phenom II family. It seems logical that new Athlon II X4 CPUs should demonstrate pretty much the same overclocking potential. However, there is always hope for a miracle and in this case it is even stronger due to the fact that Athlon II X4 are based on the new semiconductor die without the L3 cache memory. Therefore, we couldn’t leave out our overclocking experiments this time, too.
All experiments were performed on the same platform as was used for performance tests. We would only like to add that we used Scythe Mugen cooler with a Noctua NF-P12 fan for CPU cooling.
Since both Athlon II X4 processors launched today do not belong to the Black Edition series, they cannot be overclocked by raising the multiplier. To increase the frequency over the nominal values we must raise the clock generator frequency. However, this is very easy to do: new processors work perfectly fine with the clock generator frequency increased quite significantly.
For example, by raising the processor Vcore 0.175 V above the nominal we managed to overclock our Athlon II X4 630 to 3.64 GHz by simply increasing the clock generator frequency to 260 MHz.
Unfortunately, we couldn’t overclock our Athlon II X4 630 any further, because the CPU lost stability. It suggests that the frequency potential of the Propus core for some reason turned out lower than that of the Deneb core equipped with an L3 cache memory.
The results of Athlon II X4 620 overclocking only confirmed our concerns. This CPU overclocked only to 3.57 GHz with the core voltage increased by 0.15 V above the nominal.
To make sure that we cover all aspects of Athlon II X4 overclocking, we decided to test their performance in overclocked mode and compare the results against the performance of overclocked Core 2 Quad Q8200. For this test we increased the frequency of the Core 2 Quad processor to a pretty typical value of 3.4 GHz obtained as 7 x 486 MHz. The opponent will be Athlon II X4 630 overclocked to 3.64 GHz set as 14 x 260 MHz. all other system settings are given in the table below:
As we see, during overclocking Intel processor won a more convincing victory over the new Athlon II X4 than in nominal mode. And this is not surprising at all. Our Core 2 Quad Q8200 processor was overclocked by 45% above the nominal, which is in fact far not the limit for this CPU modification. Athlon II X4 could barely overclock by 30%. In other words, although the overclocking potential of Athlon II X4 is not as modest as that of the old Phenom X4, but it still leaves much to be desired.