Other characteristics

Data transfer rate (as of 2008) at the inner zone ranges from 44.2 MB/s to 74.5 MB/s, while the transfer rate at the outer zone ranges from 74.0 MB/s to 111.4 MB/s.[citation needed] In contrast, the first PC drives could manage only around 40 KiB/s.
Seek time currently ranges from just under 5 ms for high-end server drives, to 15 ms for miniature drives, with the most common desktop type typically being around 9 ms.[citation needed] There has not been any significant improvement in this speed for some years. Some early PC drives used a worm-gear to move the heads, and as a result had access times as slow as 80–120 ms, but this was quickly improved by voice-coil type actuation in the late 1980s, seeing access times reduce to around 20 ms.
Power consumption has become increasingly important, not just in mobile devices such as laptops but also in server and desktop markets. Increasing data center machine density has led to problems delivering sufficient power to devices, and getting rid of the waste heat subsequently produced, as well as environmental and electrical cost concerns (see green computing). Similar issues exist for large companies with thousands of desktop PCs. Smaller form factor drives often use less power than larger drives. One interesting development in this area is actively controlling the seek speed so that the head arrives at its destination only just in time to read the sector, rather than arriving as quickly as possible and then having to wait for the sector to come around (i.e. the rotational latency).
Audible noise (measured in dBA) is significant for certain applications, such as PVRs digital audio recording and quiet computers. Low noise disks typically use fluid bearings, slower rotational speeds (usually 5,400 rpm) and reduce the seek speed under load (AAM) to reduce audible clicks and crunching sounds. Drives in smaller form factors (e.g. 2.5 inch) are often quieter than larger drives.
Shock resistance is especially important for mobile devices. Some laptops now include a motion sensor that parks the disk heads if the machine is dropped, hopefully before impact, to offer the greatest possible chance of survival in such an event

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