Mobile HDD Metrics

The Tech Report (with thanks to Slashdot for the heads-up) recently published a comprehensive round-up of seven 2.5" HDDs, ranging from 4200 to 7200 RPM, in both 2 MByte and 8 MByte cache flavours, and in both longitudinal and perpendicular recording varieties. When assessing speed-versus-power consumption and speed-versus-cost as you pour over the writeup's abundant data, also consider energy (the product of power times time). A faster drive may burn more power but, because it completes the desired read or write access request more quickly and therefore returns to a low power consumption mode more quickly, may have a lower energy consumption profile and therefore drain batteries more slowly.