You can refer to the article called Hard Disk Drive Power Consumption Measurements: X-bit’s Methodology Indepth for details about this test. We will measure the power draw of the drives in three modes: Idle, Random Read & Write, and Sequential Read & Write.
Unfortunately, we couldn’t perform this test for the Gigabyte i-RAM due to the specifics of its power supply. The 64GB SSD from Samsung will be compared with two 7200rpm HDDs.
The SSD consumes but slightly less power than the 2.5” Hitachi 7K200 with a spindle rotation speed of 7200rpm. As we know, HDDs of this form-factor but with lower spindle speeds require even less, so they can be even more economical than SSDs. The 3.5” Samsung SpinPoint F1 is much hungrier for power.
The SSD consumes only half the power the Hitachi 7K200 needs at random reading and writing. The Samsung SpinPoint F1 consumes about three times as much as the 7K200.
HDDs need more power for reading, but SSDs – for writing. It is easy to explain if you remember that each write operation is preceded with the erasing of data in the cell.
Flash-based drives are even more economical than HDDs at sequential operations. The difference between writing and reading is smaller here. Note that the Hitachi 7K200 consumes less power at sequential reading than at sequential writing. It’s quite different from random operations.