Atom, Athlon, or Nano? Energy-Savers Compared

Idle/Peak Power, Performance Per Watt

This is very interesting—despite completely different processor architectures and platforms, all three systems showed exactly the same idle power of 28 W. It’s amazing to see that a power-optimized Athlon 64 processor can reach the same idle power as Intel’s low-power Atom, which suffers from the unnecessary power consumption caused by the mainstream chipset. VIA’s new processor may be faster than the C7, but it cannot decrease idle power requirements any further.

We looked at peak power consumption in all of our benchmarks, but decided to take the SYSmark 2004 peak power results, as these are easy to track and not much different from what we saw using Prime95 or other tools. VIA’s low-power Nano system obviously can be the most power hungry solution as well, requiring up to 50 W of power. The AMD and Intel systems are rather close to each other—AMD did not exceed a 39 W power requirement, while Intel stays below 36 W at all times, despite its ordinary desktop chipset.

SYSmark 2004 Performance Per Watt

This is what many of you probably wanted to see most: We correlated the SYSmark 2004 scores with the Watt-hours required to complete the benchmark run. And clearly, Intel’s Atom platform is the most efficient. It offers the best SYSmark 2004 performance-–probably due to Intel’s Hyper-Threading technology and Atom’s better memory performance—and has the lowest power requirements. Please note that this result may be different in other benchmarks, depending on where the benchmark focus lies. We decided to run SYSmark, as it reflects desktop performance.

SYSmark 2004 Power Diagram

Lastly, you should have a look at our power diagram, which shows the system power consumption for every point of the duration of the SYSmark run. It shows that the VIA Nano L2100 system has the highest peak power and that the difference between idle and peak power for the Atom system is typically little, which reflects the small processor TDP of only 4 W. And the diagram also shows that the AMD system took the most time to complete this benchmark, followed by VIA’s device, while Intel’s Atom had the fastest time.

More Results: Compare with Core 2 Duo

If you want to see how the three system stack up against a Core 2 Duo E8500, please see the image gallery with additional test results