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Flash hard drives: Samsumg

 
 
Mutlley
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Posts: n/a
 
      05-25-2005
GraB <(E-Mail Removed)> wrote:

>On Wed, 25 May 2005 17:56:03 +1200, Steve <(E-Mail Removed)> wrote:
>
>>Like these? just need them to be 10 or 20GB+
>>
>>http://www.pp.co.nz/HardDiskDrives-SolidState.php
>>

>I like the MTBF, 1,000,000 hours.


Hardly the fastest transfer rate avg 4Meg/sec

I have worked with systems over the past few years that use flash roms
instead of hard disks and I'm yet to me convince. Disk corruption
seems to be the main problem compared to their HD equivalents systems
 
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Roger_Nickel
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      05-25-2005
Bruce Sinclair wrote:
> In article <(E-Mail Removed)>, -=rjh=- <(E-Mail Removed)> wrote:
>
>>Bruce Sinclair wrote:
>>
>>>In article <d716im$u6c$(E-Mail Removed)>, Nicholas Sherlock

>>
>><(E-Mail Removed)> wrote:
>>
>>>>steve wrote:
>>>>
>>>>>Flash hard drives will be standard in all PCs within a very few years, I
>>>>>would think.
>>>>
>>>>The price will have to reduce massively. Although prices are falling,
>>>>have you seen the prices for 2gb flash cards recently? AFAICS, with
>>>>billions of discrete elements in each chip, won't there be a high
>>>>failiure rate?

>
>
>>>The great joy of integrated circuits is that it's effectively one thing to
>>>fail. While there might be millins of 'transistor equivalents' ... these
>>>don't enter the equation. As it was once explained to me ... we wouldn't
>>>have video recorders if they built them out of discrete transistors

>
>
>>But, I thought the main poblem with flash memory is that it *does* fail
>>after a relatively small number of writes? What is Samsung doing here
>>that is different?

>
>
> Why should it ? I have not heard of a failure of any 'pen drives' ... even
> though they get a hard life. Sure, that sort of life is not the kind of
> write performance you'd probably get as a 'hard drive'.
>
> (Anyone else had any of these fail or heard of it ?)
>
> I can see the possibilities for a few more failures than memory sticks that
> are physically inside computers (as they have a few extra mechanical bits
> that get used occasionally ... and peopel can be a bt rough ) ... but why
> would they fail any more often otherwise ? .. and if they are installed as
> "hard drives", that connection/disconnection stress is minimised too ...
> isn't it ?
>
>
>
>
> Bruce
>
>
> -------------------------------------
> The power of accurate observation is commonly called cynicism by those who have not got it.
> - George Bernard Shaw
> Cynic, n: a blackguard whose faulty vision sees things as they are, not as they ought to be.
> - Ambrose Bierce
>
> Caution ===== followups may have been changed to relevant groups
> (if there were any)

Most flash memery is rated for around 2,000,000 read write cycles. It seems that
modern flash memory can monitor R/W cycles on a sector by sector basis and move
data around to distrubute R/W activity across the whole drive. This is somewhat
similar to the error recovery built into traditional hard disks. 2,000,000 read
write cycles could soon come up in a flash disk in use as cache memory.
 
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Matthew Poole
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      05-25-2005
On Thu, 26 May 2005 11:31:01 +1200, someone purporting to be Roger_Nickel
doth scrawl:

> Bruce Sinclair wrote:
>> In article <(E-Mail Removed)>, -=rjh=- <(E-Mail Removed)>
>> wrote:

*SNIP*
> traditional hard disks. 2,000,000 read write cycles could soon come up in
> a flash disk in use as cache memory.

Whenever someone asks on Slashdot or one of the Unix newsgroups about
using a flash disk to build a network appliance, one of the first caveats
mentioned is that you never, ever, ever put your log or tmp directories on
flash media. You put tmp onto a memory drive (RAM is cheap, after all),
and you use remote logging or NFS mounts to put the logs onto a system
with real disks.
Some of the servers at work would blow through 2m write cycles within a
week.

--
Matthew Poole
"Don't use force. Get a bigger hammer."

 
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Bruce Sinclair
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      05-26-2005
In article <(E-Mail Removed)>, -=rjh=- <(E-Mail Removed)> wrote:
(snip)
>It is nothing to do with physical handling of the devices at all - there
>is no doubt that these devices are physically very rugged - and I doubt
>that even early pen drives would have gone through enough write cycles
>for failure to occur; however, for a hdd replacement, the situation is
>quite different.


(snip)

Interesting - thanks

Bruce


-------------------------------------
The power of accurate observation is commonly called cynicism by those who have not got it.
- George Bernard Shaw
Cynic, n: a blackguard whose faulty vision sees things as they are, not as they ought to be.
- Ambrose Bierce

Caution ===== followups may have been changed to relevant groups
(if there were any)
 
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Mutlley
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Posts: n/a
 
      05-26-2005
http://www.velocityreviews.com/forums/(E-Mail Removed)z (Bruce Sinclair)
wrote:

>In article <(E-Mail Removed)>, Mutlley <(E-Mail Removed)> wrote:
>>GraB <(E-Mail Removed)> wrote:
>>
>>>On Wed, 25 May 2005 17:56:03 +1200, Steve <(E-Mail Removed)> wrote:
>>>
>>>>Like these? just need them to be 10 or 20GB+
>>>>
>>>>http://www.pp.co.nz/HardDiskDrives-SolidState.php
>>>>
>>>I like the MTBF, 1,000,000 hours.

>>
>>Hardly the fastest transfer rate avg 4Meg/sec
>>
>>I have worked with systems over the past few years that use flash roms
>>instead of hard disks and I'm yet to me convince. Disk corruption
>>seems to be the main problem compared to their HD equivalents systems

>
>Is that lack of verification of the write, stability of the written data or
>.. ?
>
>
>
>Bruce


Hard to say. These are small voicemail systems and run MSDOS 6.22
Y2K version. We have found that DOS and flash roms are not always
compatible and we have to do cache flushing quiet regular..
 
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-=rjh=-
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Posts: n/a
 
      05-26-2005
Bruce Sinclair wrote:
> In article <(E-Mail Removed)>, -=rjh=- <(E-Mail Removed)> wrote:
>
>>Bruce Sinclair wrote:
>>
>>>In article <d716im$u6c$(E-Mail Removed)>, Nicholas Sherlock

>>
>><(E-Mail Removed)> wrote:
>>
>>>>steve wrote:
>>>>
>>>>>Flash hard drives will be standard in all PCs within a very few years, I
>>>>>would think.
>>>>
>>>>The price will have to reduce massively. Although prices are falling,
>>>>have you seen the prices for 2gb flash cards recently? AFAICS, with
>>>>billions of discrete elements in each chip, won't there be a high
>>>>failiure rate?

>
>
>>>The great joy of integrated circuits is that it's effectively one thing to
>>>fail. While there might be millins of 'transistor equivalents' ... these
>>>don't enter the equation. As it was once explained to me ... we wouldn't
>>>have video recorders if they built them out of discrete transistors

>
>
>>But, I thought the main poblem with flash memory is that it *does* fail
>>after a relatively small number of writes? What is Samsung doing here
>>that is different?

>
>
> Why should it ? I have not heard of a failure of any 'pen drives' ... even
> though they get a hard life. Sure, that sort of life is not the kind of
> write performance you'd probably get as a 'hard drive'.
>
> (Anyone else had any of these fail or heard of it ?)
>
> I can see the possibilities for a few more failures than memory sticks that
> are physically inside computers (as they have a few extra mechanical bits
> that get used occasionally ... and peopel can be a bt rough ) ... but why
> would they fail any more often otherwise ? .. and if they are installed as
> "hard drives", that connection/disconnection stress is minimised too ...
> isn't it ?


It is nothing to do with physical handling of the devices at all - there
is no doubt that these devices are physically very rugged - and I doubt
that even early pen drives would have gone through enough write cycles
for failure to occur; however, for a hdd replacement, the situation is
quite different.

==========
http://www.cotsjournalonline.com/hom...php?id=100053:

Write Endurance

Early adopters of flash for storage suffered write endurance limits in
many applications because the number of cycles was limited to about
10,000. Today it is common to find flash device write endurance over one
million cycles and the use of defect management techniques to take care
of infant failures. With modern write endurance and defect management
techniques there are very few applications that are limited by write
endurance.
=============

It may be historical now, but certainly has been a problem in the past -
Intel have a patent on wear levelling for flash memory - ie, the
devices do wear, but compensating for this and employing error
correction can achieve acceptable lifetimes.

http://www.freepatentsonline.com/5341339.html

We haven't seen widespread use of flash hard drives before, so whether
the failure rate of these devices in the real world is acceptable
remains to be seen. Given the short lifecycle of tech products, and how
crappy a lot of them are, I doubt if Samsung will really care.*

Following article is very interesting, and shows just how much is going
on inside and around flash memory; it isn't as simple or straightforward
as you might think.

http://www.storagesearch.com/siliconsys-art1.html

Wear seems to be inherent in the system, and considerable effort has to
go into compensating for it.

cheers

*For example, I read somewhere recently that the lifetime of an Ipod
drive is measured in *tens* of hours (I don't believe it) but this
doesn't matter because it spins for very short periods of time - while
it loads data into cache. And the drive will still last longer than the
battery, anyway



 
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-=rjh=-
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      05-26-2005
thing wrote:
> steve wrote:
>
>> thing wrote:
>>
>>> Would make interesting boot disks.....one flash drive v 2 scsi/sata
>>> drives and a HW raid controller....might actually work out
>>> cheaper....and faster.
>>>
>>> Except of course if "someone" developed a read only region for the OS
>>> and it was pre-installed with a MS OS.....

>>
>>
>>
>> I'm sure you'd be able to buy ones that didn't...or could be hacked.

>
>
> Im sure you could, of course most computer users will simply buy a
> Windows PC "that cant be hacked", only to find if they want to
> swap to Linux or OS/2 (grin) it cant be done on that hardware.
>
> Im sure BG gets wet dreams over that possibility....


I would not be surprised if MS produces a low end Windows "lite"
hardware and software product for home users.

Xbox is exactly that, but is aimed too much at gamers; but it
demonstrates that MS is willing to drop a vast amount of money into
something that may takes years to become profitable.

A low end system for people who only want to check email, surf the web,
chat and upload photos could be successful for a company like MS. Tie
the OS into the hardware in a way that makes it difficult to fiddle
with; add a subscription service (which is what Xbox Live is); do
automatic online updates as Windows does now; and MS could make money at
this. They've got a size and brand advantage over any other company that
has or would like to try this.

You could buy the system at Xbox prices, and pay a monthly subscription
through your ISP - Xtra would go for this. Instead of having to set up a
separate ADSL or dialup modem, this could be incorporated and ready to
run out of the box.

Many home PC users find their software far too complex to use, and it
far exceeds their functional requirements. If this was dumbed down and
had extra MS online products built into it - like MS searching, a
dedicated hotmail client, etc, it could be easy to use. The market isn't
as glamorous as games, but overall I would guess it would be bigger.

MS would be entering an area that doesn't conflict with their OEMs; and
they must have noticed the stir that the Apple Mac Mini has made in some
circles. It would be a different market, but still...

Within two years, I reckon. It isn't a new idea, but hardware is getting
really cheap and there are more compelling online applications now.
 
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Lawrence DčOliveiro
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Posts: n/a
 
      05-26-2005
In article <42952dbe$(E-Mail Removed)>, -=rjh=- <(E-Mail Removed)>
wrote:

>Many home PC users find their software far too complex to use, and it
>far exceeds their functional requirements.


This is a load of nonsense. People won't buy less-functional software,
because they think they're getting less value for their money. Features
sell. That's how the market works.
 
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Lawrence D'Oliveiro
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Posts: n/a
 
      05-26-2005
In article <(E-Mail Removed)>,
Mutlley <(E-Mail Removed)> wrote:

>I have worked with systems over the past few years that use flash roms
>instead of hard disks and I'm yet to me convince. Disk corruption
>seems to be the main problem compared to their HD equivalents systems


Isn't that exactly what happened to the Spirit Mars Rover?
 
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Roger Johnstone
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      05-26-2005
In <F_5le.2891$(E-Mail Removed)> Bruce Sinclair wrote:
>
> The great joy of integrated circuits is that it's effectively one
> thing to fail. While there might be millins of 'transistor
> equivalents' ... these don't enter the equation. As it was once
> explained to me ... we wouldn't have video recorders if they built
> them out of discrete transistors


We might not have _affordable_ video recorders, but the first video tape
recorders were developed in the early 1950s, and it's likely they
wouldn't have had any transistors in them at all. Of course they were
slightly bigger and more expensive than the versions sold today )

--
Roger Johnstone, Invercargill, New Zealand
http://vintageware.orcon.net.nz/
__________________________________________________ ______________________
No Silicon Heaven? Preposterous! Where would all the calculators go?

Kryten, from the Red Dwarf episode "The Last Day"
 
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