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 2TB WD Caviar needs more power than the others on the 12V line when starting up – this is the effect of its extra platter. With Seagate’s products, we can see some progress in the new series: the 1.5TB model is but a little more economical than its predecessor whereas the new Barracuda 7200.12 drive is much more modest. It needs 1 ampere less on the 12V line.
The idle mode results are very interesting. Everything is logical with the new drives from Seagate: the electronics has the same power consumption in the Barracuda 7200.11 models and has become somewhat more economical in the 7200.12. The 12V consumption of these HDDs is proportional to the number of platters in them. The 2TB WD Caviar Green is somewhat disappointing. The 12V consumption might have been predicted because the addition of yet another platter has its consequences (although 1.5 watts is rather too much) but the twice higher consumption of the electronics is hard to explain.
The Green drives are beyond competition at random reading. Still, you should note how high the consumption of the 2TB model has grown up. It pays a lot for the high recording density. Surprisingly enough, the Seagate Barracuda 7200.12 is not much better than its opponents: we should expect more from a disk with two platters.
Deferred writing algorithms come into play at random-address writing. It is interesting to compare the consumption of the electronics with what we’ve seen at reading: it grows up with Western Digital’s products but drops with Seagate’s HDDs. The Green drives are better overall but the high consumption of the 2TB model’s electronics should be noted. There is an interesting thing we can note about Seagate’s products: the new Barracuda 7200.12 is the best of all the 7200rpm drives in this review but is not superior to them in terms of 12V consumption (although it should be theoretically as it has fewer platters). The WD Caviar Black is the worst drive in this test. It has to pay for its advanced electronics and quick heads.
The WD Caviar Green are also better at sequential reading but the 2TB model is just a little better than the 1TB Seagate Barracuda 7200.12: the economy due to the reduced spindle speed is eaten up by the consumption of the platters. However, the 2TB model looks very economical if you compare it with the 1.5TB Seagate.
The Seagate Barracuda 7200.12 is ahead of the 2TB Caviar Green at sequential writing as it has fewer platters and more economical electronics.