You can refer to our article called Hard Disk Drive Power Consumption Measurements: X-bit’s Methodology in Depth for details on this test. We will just list the specific modes we measure the power consumption in:
- Start (the current the drive consumes when starting up)
- Idle (the drive is not accessed at all, but it is turned on and ready to work)
- Random Read and Write
- Sequential Read and Write
Let’s check out each mode one by one.
The Constellation ES is not included here as it consumes electric current from two lines, making the comparison unfair. The Momentus XT is right in between the two HDDs we already tested before whereas the Toshiba requires a lot of power, over 1 ampere. Roughly speaking, it will not be powered up even by two USB ports!
The Momentus XT shows itself very economical in idle mode, requiring no more than half a watt. If you read our latest 2.5-inch HDD report, you already know that the HDD just turns off its motor if not accessed for a certain period of time. Considering that it has 4 gigabytes of data in flash memory, this is a very reasonable power-saving solution.
Take note that the 3.5-inch HDD is much more voracious than its smaller counterparts. It needs about five times as much power when idle. And where does this power go? Yes, it is dissipated as heat. This difference may be crucial in some situations.
At random-address operations the 2.5-inch drives are very close to each other both at reading and writing. The difference between the models is a mere 10%. Compared to them, the 3.5-inch Constellation ES is a glutton as it eats three times more power!
When processing sequential requests, the HDDs of different form-factors get somewhat closer to each other, yet the 3.5-inch one still consumes more than two times as much power as its opponents. The Hitachi 7K500 wins this test but by a very small margin.