You can refer to our article called Hard Disk Drive Power Consumption Measurements: X-bit’s Methodology Indepth for details on this test. We’ll just list the specific modes we measure the power consumption in:
- Start (the current the drive consumes when speeding up its spindle)
- 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 HDD from Western Digital requires the highest current to start up. It is the only drive to need more than 1 ampere. This means even two USB ports simultaneously won’t be enough to power it up in a mobile rack (to remind you, one USB port guarantees a current of no more than 0.5 amperes; any load above this value is beyond the requirements of the USB specification). The drive seems to require such a high current to switch into operation-ready mode in the shortest time possible. That’s good, but we guess the developer should have stopped at 1 ampere.
The Samsung is the most economical drive in the test, requiring only two thirds of the current demanded by the Western Digital. The Hitachi needs somewhat more, taking second place.
Most of the drives need somewhat less than 1 watt in idle mode. The good exceptions are the Toshiba and the Fujitsu.
It is the electromechanical section of a HDD that consumes most power during random reading whereas the electronics is mostly idle. Here, the Seagate is by far the most economical drive. Recalling its poor results at random reading (and its high response time), we can suspect that its heads unit has a weaker but more economical actuator. The leader is followed by the Samsung and Toshiba that have similar results. The HDD from Western Digital is the most voracious drive in this test.
When a hard drive is performing random writing, its electronics consumes more and the overall power consumption grows up. The standings differ somewhat because the growth is different with each HDD. The Seagate is still the most economical model (we can also recall that it showed no deferred writing in IOMeter Database and had low results at random writing) while the Fujitsu and Hitachi share the title of the most voracious model. The low growth of power consumption of the Western Digital drive is somewhat surprising: its electronics either consumed a lot at reading or is very power efficient.
The difference between reading and writing is smaller when it comes to sequential operations. The Seagate is the most economical again whereas the drive from Western Digital is still very hungry, asking for 3 watts of power. That’s quite a lot and exceeds the capability of one USB port. You should keep this fact in mind if you are choosing a hard disk to use in a mobile rack. The high speed of the HDD from Western Digital is accompanied with high power consumption.