Improve company productivity with a Business Account.Sign Up

x
?
Solved

Hard Drive - Seek Time, Write Time, and Latency - Looking for clarification

Posted on 2013-01-30
4
Medium Priority
?
1,134 Views
Last Modified: 2013-02-24
These are the Seek Time, Write Time, and Latency specs for my old hard drive (Seagate Momentus 7200.4 ST9500420ASG 500GB 7200 RPM).

Average Seek Time = 11ms
Average Write Time = 13ms
Average Latency = 4.17ms

What's the total Read Time? Here's my guess:
Average Total Read Time = Average Seek Time + Average Latency
Is this correct?

What's the total Write Time? Here's my guess:
Average Write Time = Average Write Time  + Average Latency
Is this correct? Or, do I omit Latency because it's already included in the Average Write Time?
0
Comment
Question by:jdana
  • 2
4 Comments
 
LVL 30

Accepted Solution

by:
Duncan Meyers earned 652 total points
ID: 38836766
Yes - latency is typically one half of a rotation. Total read time should include settling time and the time to read a sector. Your calculation for write time is correct assuming that the specs have included seek time in the write time. If not, you need to add average seek time.

It's quite a slow drive. A 10k enterprise drive has latency around 3.5mS and average seek times around 2.5mS.
0
 
LVL 93

Assisted Solution

by:nobus
nobus earned 648 total points
ID: 38838686
0
 

Author Closing Comment

by:jdana
ID: 38923005
Thanks!
0
 
LVL 30

Expert Comment

by:Duncan Meyers
ID: 38923999
Thanks! Glad I could help.
0

Featured Post

Get 10% Off Your First Squarespace Website

Ready to showcase your work, publish content or promote your business online? With Squarespace’s award-winning templates and 24/7 customer service, getting started is simple. Head to Squarespace.com and use offer code ‘EXPERTS’ to get 10% off your first purchase.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

This article shows how to use a free utility called 'Parkdale' to easily test the performance and benchmark any Hard Drive(s) installed in your computer. We also look at RAM Disks and their speed comparisons.
The article describes step by step how to validate the SRA software certificate once installed on the Site Recovery Manager server. I hope it will be very useful for all administrators of virtualized environments.
This video teaches viewers how to encrypt an external drive that requires a password to read and edit the drive. All tasks are done in Disk Utility. Plug in the external drive you wish to encrypt: Make sure all previous data on the drive has been …
How to fix display issue, screen flickering issue when I plug in power cord to the machine. Before I start explaining the solution lets check out once the issue how it looks like after I connect the power cord. most of you also have faced this…

606 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question