How Does RPM Affect a Hard Drive?

By Gregory Hamel

Hard Drive RPM Basics

A hard disk drive is a device in a computer which stores digital data on a rotating magnetically charged disc called a platter, which resembles a small metallic compact disk. The term RPM stands for rotations per minute, which indicates how many times the platter in a disk drive can complete a 360-degree rotation each minute. Since hard drives must spin in order to access and transfer data, a higher RPM hard drive will be able to access and transfer data faster. During operation, higher RPM is most noticeable when launching new programs that force the computer to access the hard drive, or when writing transferring large amounts of data to or from the hard drive. A hard drive's RPM will have less impact on the speed of a computer in running a program after it is launched, since necessary data will be saved to the computer's RAM for faster access.

Higher RPM Means More Energy Usage

In general, higher RPM means equates to superior hard drive performance, but it also has a couple of drawbacks. In order to achieve higher rotational speeds, hard drives must draw more power to overcome increased wind resistance. This means higher RPM drives will put more strain on a power supply, which can add up when several high RPM drives are installed in one computer. Average disk drives rotate at 5400 or 7200 RPM. High-end drives which rotate at 10,000 or 15,000 RPM create so much wind resistance that disk memory capacity must often be compromised by shrinking the diameter of the platter in order to create a drive which runs effectively and does not draw too much power. Therefore, drives with very high RPM may not be economical as data storage.

Other Considerations

While a hard drive with a high RPM will improve overall computer performance and especially the time to start programs and transfer data, upgrading a computer's hard drive will likely not lead to large increase in performance. When a computer runs, the hard drive stores data to RAM, which is able to transfer it more quickly to the processor for use. As a result, the processing and multitasking speed of a computer is more often limited by inadequate RAM or a slow processor, than hard drive RPM. High-RPM hard drives are often used by hard core gamers and techies that like to have computers which operate as fast as technology will allow, but for normal users a hard drive average RPM and high storage capacity should be satisfactory.