Overclocking

As we have already pointed out in our previous article called ?a href="/articles/cpu/display/amd-energy-efficient.html" target="_blank">AMD’s Response to Intel Conroe: Energy Efficient Athlon 64 X2 CPU? AMD Energy Efficient processors do not always boast satisfactory overclocking potential. Athlon 64 X2 3600+ is one of those processors, so we decided not to pin too many hopes upon its overclocking potential.

The practical experiments were conducted on a traditional testbed including the following hardware components: ASUS M2N32-SLI Deluxe mainboard based on Nvidia nForce 590 SLI chipset, Corsair Twin2X2048-8500C5 memory and PowerColor X1900 XTX 512MB graphics card. The processor was cooled with Zalman CNPS9500 AM2 air-cooler. Since the maximum clock frequency multiplier of the

Athlon 64 X2 3600+ is locked at 10x maximum, these CPUs can only be overclocked by raising the clock generator frequency. In this case we had to reduce the multiplier for the memory frequency and HyperTransport bus connecting the CPU with the SPP in order to ensure that all other subsystems of the test platform work stably.

We worked to reveal the maximum clock speed this processor could work at by raising the Vcore from the nominal 1.25V to 1.5V. Note that this Vcore increase is not really dangerous for the CPU, because they build Athlon 64 X2 3600+ using the same semiconductor dies as in the “normal?dual-core processors with the nominal core voltage of 1.3-1.35V.

In this case we managed to retain system stability not only in general benchmarking applications but also in the special tests (such as S&M, in the first place) with the clock generator frequency at 260MHz. Further frequency increase affected the system operational stability, although it would still boot at up to 275MHz frequency.

So, we would consider 2.6GHz clock speed the final result of our Athlon 64 X2 3600+ overclocking experiment.

As a result, our Athlon 64 X2 3600+ sample overclocked by 30%, i.e. up to the level of Athlon 64 X2 5000+. Note that this overclocking can be quite efficient from the performance prospective, because the clock generator frequency of 260MHz also allows overclocking the memory. Even the minimal memory frequency divider (CPU Frequency / 5) that ensures DDr2-800 SDRAM support in the nominal mode allowed increasing the memory frequency to 1040MHz.

There are a lot of overclocking-friendly memory modules in the market these days. Take, for instance, Corsair Twin2X2048-8500C5. Although, unfortunately, we had to set the maximum timings and 2T Command Rate, the performance turned out better than in case of DDR2-800 SDRAM with 4-4-4- timings and 1T Command Rate.

So, you can expect the overclocked to 2.6GHz Athlon 64 X2 3600+ to reach the performance level of the top AMD Athlon 64 X2 processors. And now we are going to perform a few additional tests to prove this statement.