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Is there a formula to approximate data transfer times from hard disks?

For example, suppose I want to retrieve a 512 byte sector of data off a 7200RPM hard disk with an average seek time of 9 milliseconds, and a nominal data transfer rate of 15MB/s. What is the average transfer time?

I'm trying to come up with a formula for this so I can re-use it.

Falcon Momot
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MarkNinja
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  • What's the problem you're trying to solve here? There are a few confounding factors that can make a direct answer to your question quite inaccurate. Averages can be surprisingly misleading too. If we knew more about your problem we could provide better answers. – Ladadadada May 22 '13 at 18:06

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I'd say it's seek time + rotational delay + data transfer

Thus, if I'm not mistaken it's 9 ms + 4,2 ms + 0,0325 ms → 13.23 ms

poige
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    @MarkNinja The rotational delay is calculated as (60 seconds / 7200 rpm / 2) = 0,004167 seconds (approx. 4,2 ms). Also take a look at this course script for further detail: http://cseweb.ucsd.edu/classes/wi01/cse102/sol2.pdf – the-wabbit May 22 '13 at 08:34