Latency is simply defined as the time delay from the server's request for data until the data begins to be read or written. For rotating disks, latency is an initial delay in reading or writing data caused by the time for the heads to move to the proper track and then the time for the desired data to rotate under the head. For a high-end disk, the total latency is about .01 second. As disk drive latencies are caused by mechanical operations, they are glacial when compared to latency of semiconductor memory. Latency for Solid-State Disks is typically in the 10-microsecond range, 1000 times less than rotating storage.
Low Latency Data Access
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