decoration decoration
Stories

GROKLAW
When you want to know more...
decoration
For layout only
Home
Archives
Site Map
Search
About Groklaw
Awards
Legal Research
Timelines
ApplevSamsung
ApplevSamsung p.2
ArchiveExplorer
Autozone
Bilski
Cases
Cast: Lawyers
Comes v. MS
Contracts/Documents
Courts
DRM
Gordon v MS
GPL
Grokdoc
HTML How To
IPI v RH
IV v. Google
Legal Docs
Lodsys
MS Litigations
MSvB&N
News Picks
Novell v. MS
Novell-MS Deal
ODF/OOXML
OOXML Appeals
OraclevGoogle
Patents
ProjectMonterey
Psystar
Quote Database
Red Hat v SCO
Salus Book
SCEA v Hotz
SCO Appeals
SCO Bankruptcy
SCO Financials
SCO Overview
SCO v IBM
SCO v Novell
SCO:Soup2Nuts
SCOsource
Sean Daly
Software Patents
Switch to Linux
Transcripts
Unix Books

Gear

Groklaw Gear

Click here to send an email to the editor of this weblog.


You won't find me on Facebook


Donate

Donate Paypal


No Legal Advice

The information on Groklaw is not intended to constitute legal advice. While Mark is a lawyer and he has asked other lawyers and law students to contribute articles, all of these articles are offered to help educate, not to provide specific legal advice. They are not your lawyers.

Here's Groklaw's comments policy.


What's New

STORIES
No new stories

COMMENTS last 48 hrs
No new comments


Sponsors

Hosting:
hosted by ibiblio

On servers donated to ibiblio by AMD.

Webmaster
Wrong! | 283 comments | Create New Account
Comments belong to whoever posts them. Please notify us of inappropriate comments.
Wrong!
Authored by: tiger99 on Wednesday, November 07 2012 @ 01:20 PM EST
Write cycles are just as damaging as erase cycles. And, it is certain disreputable manufacturers of storage products, basically only packagers, who are claiming 100k cycles. The chip manufacturers generally claim 10k.

Now with wear levelling it may seem that they will last quite a long time, but it depends entirely on how much free space there is on the device. If, in the extreme case, only one sector remains free, 10k writes will kill it. I have seen some other incorrect calculations not so long ago, which also made the same error of using total device capacity in the calculation. It is not, it is always the free space that matters, for any solid state memory with wear levelling.

Nevertheless, if care is taken to ensure that there is always a large amount of free space, say 50%, and the kernel "swappiness" is set to minimum, solid state storage devices, such as USB sticks or SD cards, are fit for the envisaged purpose, where a life of a few years is all that will be required. But ferroelectric RAM (FRAM), which is non-volatile and has a much larger capability for write cycles (also per byte, not per sector) is coming along and when its storage density becomes comparable to flash, the limited life will largely disappear. I am not convinced that anyone knows yet just how many write cycles a FRAM cell will tolerate, and whether it is infinite or just a very large number, but it is certainly much better than flash. And, it works more or less like RAM, i.e. almost as fast to write as to read, and every bit independently changeable. See here for example.

[ Reply to This | Parent | # ]

  • Wrong! - Authored by: DieterWasDriving on Wednesday, November 07 2012 @ 03:18 PM EST
  • Wrong! - Authored by: Anonymous on Thursday, November 08 2012 @ 08:51 AM EST
Groklaw © Copyright 2003-2013 Pamela Jones.
All trademarks and copyrights on this page are owned by their respective owners.
Comments are owned by the individual posters.

PJ's articles are licensed under a Creative Commons License. ( Details )