X-bit labs

AMD Athlon 64 FX-60 CPU Review (page 3)

Category: CPU

by Ilya Gavrichenkov

[ 01/09/2006 | 09:01 PM ]

Power Consumption

Well, AMD did everything necessary to keep the power consumption and heat dissipation of the new Athlon 64 FX-60 within the same boundaries as the corresponding parameters of the top dual-core CPUs from the Athlon 64 X2 family. This requirement is determined primarily by the contemporary mainboards, which voltage regulator is not designed to support higher electrical power. By the way, the upcoming AMD platform that should be launched in Q2 2006, Socket M2, will support CPUs with the typical heat dissipation of up to 125W. It means that in the near future AMD will be able to continue raising the working frequencies of its CPUs without shifting to the new manufacturing process. And in the meanwhile, they managed to reach the 2.6GHz frequency for Toledo core by lowering the processor Vcore.

However, this is all pure theory. How did the power consumption of the new Athlon 64 FX-60 processor change compared with that of the predecessor, Athlon 64 X2 4800+? To answer this question we carried out a short test session where top AMD and Intel processors took part.

The diagram displays the maximum CPU power consumption achieved during our practical tests. As usual, the CPUs were loaded to their maximum with the help of S&M utility. As for the measurement techniques, we measured the current that goes through the CPU power circuitry on the mainboard. So, the numbers given below do not take into account the efficiency of the CPU voltage regulator laid out on the mainboard.

According to the obtained results, a few small losses couldn’t help AMD here. Despite all the tricks, Athlon 64 FX-60 consumes more power than the Athlon 64 X2 4800+. Although, the electrical and thermal parameters of the new Athlon 64 FX-60 do not exceed any critical values. Moreover, this CPU is much more economical than the competitor’s solution based on the new 65nm Presler core. Thus, the power consumption of the Pentium Extreme Edition 955 exceeds the power consumption of Athlon 64 FX-60 by well over 40% with all the resulting consequences. So, K8 architecture has once again proven its superiority over Intel’s NetBurst.

Here I would like to stress that dual-core AMD processors consume much more power than their single-core fellows. This can be explained by the relatively small difference in their working frequencies. As for Intel, they do their best to level out the power consumption of their single-core and dual-core solution by significantly reducing the clock speed of the latter ones.

As for the thermal and electrical characteristics of the new Athlon 64 FX-60 in idle mode, I would like to stress here that this processor supports Cool’n’Quiet technology. In idle mode this processor can slow down to 1.2GHz clock speed and drop the Vcore to 1.1V. In this case the power consumption reduces to 8.5W, which turns Athlon 64 FX-60 into a very economical CPU. However, they could have achieved even better effect if the two cores of the Athlon 64 FX-60 processor could switch to power saving mode independently. However, this feature is most likely to be implemented only in those dual-core AMD processors that will be targeted for the mobile market segment.