How Much Power Does Low-Voltage DDR3 Memory Really Save?

Benchmark Results: Multi-Thread And Overall Efficiency

Multi-Thread Efficiency

The multi-threaded workload terminates quicker on the two low-voltage configurations. But again, the difference is really small.

Average power consumption during our multi-threaded applications workload decreased…

…along with the total power required to tackle the workload.

Overall Efficiency

Overall, runtime for our full efficiency workload (single- and multi-threaded applications) decreased by only a few seconds.

At the same time, the total power required decreased slightly…

…together with the average system power. Let’s relate performance to power consumption.

As you can see, efficiency expressed in performance per watt (runtime relative to total power used) increases by 1.96% with DDR3-1333 going from 1.5 V to 1.25 V and by 2.01% on DDR3-1600 at 1.35 V vs. 1.5 V. Again, this isn't a lot alongside a fast Phenom II X6 and a powerful Radeon HD 5850 graphics card, but if you were to use low-power components, then the efficiency improvement would naturally be a few percent higher.