Benchmark Results: Power And Efficiency
This is interesting. Both drives require the same 0.8W at idle.
At peak throughput, we measured 2.7W on the three-platter 1TB drive, while the 640GB, two-platter drive consumed 2.6W.
The three-platter drive clearly requires more power when providing a defined data stream, such as HD video.
Throughput performance per watt, and hence power efficiency, is better on the 12.5 mm drive, as it delivers more throughput at slightly less power.
The contrary applies in the workstation efficiency test, where a large number of I/O operations per second is required. Apparently, the 640GB, two-platter model is faster.