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Power Consumption

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.

Fujitsu’s HDDs are the most moderate ones in terms of startup current. Even the 4-platter Fujitsu is highly economical. We might commend the Hitachi 15K147 as well, but its low 12V consumption is combined with a rather high power draw on the 5V line. Seagate’s HDDs of the two latest series and the Seagate NS.2 are equipped with the most economical electronics but each of them needs nearly 3 amperes on the +12V line, which is quite a lot. Hopefully, this current is only necessary to spin the platters up as quickly as possible.

The Maxtor behaves interestingly in idle mode: its voracious electronics consume more than its mechanics! The same three series from Seagate are the most economical in terms of 5V consumption. Now we can see the strong point of the Seagate NS.2. With its 4-platter design is needs less power than any other product in this test. It is cooler as the consequence, which is important for data centers and server racks with multiple disks inside. Fujitsu’s single- and dual-platter models are overall more economical and cooler in comparison with their opponents.

When doing random reading, all the HDDs need more power from the 12V line because they have to move their heads around a lot. As a result, nearly every model, except for the highly economical 10,000rpm Seagate NS.2 and the modest single-platter Fujitsu MBA3 RC, goes beyond 10W, the 4-platter and many 2-platter models even exceeding 15W. None of the 15,000rpm drives can be viewed as economical, so maximum-density models seem to be preferable as you can use them to build a disk subsystem with lowest heat dissipation and power consumption (by using models with fewer platters) or by reducing the number of disks.

We have to name the most voracious 2-platter drives that match 4-platter models in temperature and power consumption. These are the Maxtor (its old electronics and powerful heads actuator consume a lot) and the Seagate 15K.5 (its electronics is voracious, too). The 4-platter Hitachi 15K300 and Seagate 15K.5 have the highest power consumption of all, requiring over 17 watts of power!

Do compare the 5V consumption of the HDDs at random reading and in idle mode. You will see that many drives consume more power from the 5V line when idle than at work! What are they doing then? You can answer this question by monitoring the drives’ power consumption: they are doing patrol reading. That is, they are automatically reading from platters in idle mode, searching for potentially bad sectors. Enterprise requirements to reliability are so strict that even HDDs have to be constantly keeping themselves in good shape.

Fujitsu’s HDDs are again somewhat better than their opponents in terms of power consumption, the single-platter MBA3 RC even outperforming the 10,000rpm model. There are no serious changes in the standings, though. It is the second-generation drives that are the most voracious, again.

The overall picture doesn’t change much when we switch to sequential operations. The Seagate NS.2 is the most economical drive, being better than Fujitsu’s products which are in their turn are somewhat more economical than the others. The Maxtor and the Hitachi 15K147 have high power consumption on the 5V line again. Each next generation is a little more economical than the previous one if you compare models with the same number of platters and much more economical if you compare same-size models.

 
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