Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Average seek/access time of a flash memory drive

Posted on 2004-09-19
9
Medium Priority
?
1,146 Views
Last Modified: 2010-04-03
Hi Experts,

How do I know the "average access/seek time" of a flash memory drive? Is there any website that I can download the datasheet of a flash memory? I surfed around and all I got is read/write time. Is the read time = average seek time?
0
Comment
Question by:icysmarty
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 4
9 Comments
 
LVL 93

Expert Comment

by:nobus
ID: 12094481
0
 

Author Comment

by:icysmarty
ID: 12094494
I can't find the datasheet for "DiskOnKey", and it doesn't say anything about average seek time though.
0
 
LVL 93

Expert Comment

by:nobus
ID: 12094523
well there is no such thing basically; the term average access = the time it needs in average to access the data on a HDD, the seek time is the time the arm with the head takes as an average to position correctly on the data. Flash drives are Memory units, they don't have heads to be positioned.

This clear enough?
0
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Author Comment

by:icysmarty
ID: 12094539
For a flash memory, we should say average access time instead of average seek time? I guess.
So, average access time = time it takes to read the data?
I need to download a Datasheet of a flash drive to look into it. Have searched several website, and most of the information they provided is about read/write time. So, I guess that's pretty much about it?
0
 
LVL 93

Expert Comment

by:nobus
ID: 12094559
Yes, they give the data throughput rate, which is more or less the transfer speed, and that is the only figures they have: read speed and write speed
0
 

Author Comment

by:icysmarty
ID: 12094564
Do they have a datasheet?
0
 
LVL 4

Accepted Solution

by:
cyrnel earned 200 total points
ID: 12094778
Icysmarty, "average access" is a real spec separate from seek. It's traditionally meant to include the time required for an average seek plus a half rotation of the platter. Even when on the correct track the head will have to wait for the platter to rotate until the desired sector is underneath. Average Access = seek plus this latency.

Flash RAM has none of this latency or seek time. The data are available, waiting for the controller to register an address and strobe for access. Even if you count it, essentially the same activity is required before a hard drive begins to perform an access. A pen-drive with USB interface does have negligible overhead, in the form of commands sent serially, but even low-speed USB (1.5Mb/s) can move a page of text in 8ms. That's a lot of memory requests. Since access is essentially zero, more important is how quickly data moves between the flash memory and its destination. Variables will be the type of flash RAM and the interface (USB type or IDE or PCI or...) and the bandwidth available after other devices have used their portion.

Finally, don't put too much faith in datasheets. They're good for a first take but don't hang your job/grade/wealth on them without testing to verify for your application.

Dave
0
 

Author Comment

by:icysmarty
ID: 12096278
Thank you, I got it.
0
 
LVL 93

Expert Comment

by:nobus
ID: 12099712
Nice , i give you 3 answers, and finally you give the points to someone who repeats what i say !
0

Featured Post

Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

When we purchase storage, we typically are advertised storage of 500GB, 1TB, 2TB and so on. However, when you actually install it into your computer, your 500GB HDD will actually show up as 465GB. Why? It has to do with the way people and computers…
In this article we will learn how to backup a VMware farm using Nakivo Backup & Replication. In this tutorial we will install the software on a Windows 2012 R2 Server.
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 …
This tutorial will walk an individual through the process of installing the necessary services and then configuring a Windows Server 2012 system as an iSCSI target. To install the necessary roles, go to Server Manager, and select Add Roles and Featu…
Suggested Courses

721 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