In data storage, what does the term 'latency' refer to?

Latency in data storage refers to the wait time experienced before data is accessed or retrieved from a storage device. It measures the delay between the initiation of a request for data and the moment the first byte of data is available to the system. This concept is particularly important when evaluating the performance of storage systems, as higher latency can lead to slower response times and negatively impact overall system performance.

For example, in hard disk drives (HDDs), latency can be affected by factors such as the physical rotation speed of the disks, the time taken by the read/write heads to position themselves, and other mechanical delays. In contrast, solid-state drives (SSDs) tend to have lower latency due to their lack of moving parts, allowing for faster access times.

Understanding latency is crucial for administrators and IT professionals, as it helps in making informed decisions regarding storage solutions, performance tuning, and system upgrades, particularly in environments where speed and efficiency are critical.