You can refer to our 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 new Samsung EcoGreen F4EG is the only drive to differ from the others in terms of 5V consumption when starting up and the AV-GP is the most economical model in terms of 12V consumption (the 12V line powers up the motor and the heads actuator). The latter HDD is in no haste to do anything because it is not supposed to boot a computer’s OS as quickly as possible. All of the Samsung drives are economical, too. The Hitachi HDDs need somewhat more while the WD drives need the most power in this mode as they try to get ready to work as soon as possible. We can note that the 1.5-terabyte Caviar Black is more economical than its lower-capacity cousins as well as the RE4. The WD Caviar Blue is very similar to the Black series.
It is the HDDs with low spindle rotation speed that are the best of all when idle, yet their advantage is not very large. The single-platter high-speed Samsung SpinPoint F4 and the Hitachi (especially with the newer firmware) are almost as economical as the leaders. Interestingly, the electronics of the AV-GP, Caviar Black E3 and Caviar Green S8 did not switch into power-saving mode, spoiling their results.
Being the performance leaders throughout this review, the 1.5-terabyte HDDs from WD are the least economical in this test. They seem to be always keeping their read/write heads above the last requested track, ready to work.
The electronics of a hard disk drive doesn’t do anything at random reading but its mechanics has a lot of work to do, loading the 12V line. As a result, the single-platter Samsung SpinPoint F4 is the most economical. It saves on its electronics the most and works with only one platter and read/write head. The energy-efficient products go next. The three 1-terabyte drives from WD are somewhat better than the same-capacity Hitachi drives. That’s not good news for the latter as they have slower heads. What did they consume so much power for, then? The high-performance 1.5-terabyte drives from WD need the most power of all, up to 12 watts.
The 12V line is loaded less at random writing. We don’t see any significant changes in the ranks except that the Hitachi with newer firmware looks better, joining the 1-terabyte products from WD. The Samsung SpinPoint F4 has lost its top place, yet is still among the most economical drives.
The Hitachi with new firmware looks very good at sequential reading. Samsung’s HDDs have progressed in an odd way: the EcoGreen F2 needs more power from the 5V line but less from the 12V line. The 1.5-terabyte HDDs from WD are still voracious: their heads actuator is always working at full power.
The Hitachi drives lose their ground somewhat at sequential writing, even though remain at the same level with the energy-efficient products. Excepting the two high-performance and very voracious drives from WD, every HDD needs less than 7 watts, except for the WD Caviar Green S8. The newer MVW is more than 1 watt better, which cannot be explained by the difference of one platter and a couple of heads. We don’t know if this is the result of some optimizations in the newer HDD, or the lack of deferred writing affects the performance of the S8 in such a bad way.