Thursday, 28 June 2012

Calculating Average Latency (ms)



Ave. Latency = (0.5) x(60)x 1/RPM




Example:

Disk RPM =15000 or 15K

Therefore

Ave. Latency    = (0.5) x (60) x 1/15000

                        = 0.002

Or

Ave. Latency = 2ms

Similarly

10K RPM         ->         3ms

7200 RPM       ->         4.16ms

5400 RPM       ->         5.55