Migrating to an SSD

[J. P. Gilliver (John)]

In message <[email protected]>, Allen Drake

Intel's claim is actually "at least" 5 years at 20GBytes of writes per
day.

[]
I presume that's 20G randomly spread around the drive.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf

a little bit of me still feels that some southerners think we northerners are
issued at birth with doomed kestrels. - Alison Graham, Radio Times,
3-9/11/2007.

 

[Allen Drake]

In message <[email protected]>, Allen Drake

Intel's claim is actually "at least" 5 years at 20GBytes of writes per
day.

[]
I presume that's 20G randomly spread around the drive.

You know what happens when you presume don't you

 

[Char Jackson]

In message <[email protected]>, Allen Drake

Intel's claim is actually "at least" 5 years at 20GBytes of writes per
day.

[]
I presume that's 20G randomly spread around the drive.

My understanding is that it's taken care of for you automatically,
i.e., wear leveling.

 

[Yousuf Khan]

Did you mention which SSD you have? I just received number 10 a few
days ago. I have mostly Crucial and have had to update firmware twice
so far. Not a problem though.

Corsair Force 3 240GB.

 

[Yousuf Khan]

I would think it would depend on the capacity of the SSD. I use 256GB
SSDs and so far I have only used 60 GB. I do have backup HDDs
installed along with USB3 external for large video and music, etc.

No, I'm not worried about space, I bought one big enough to accommodate
everything that I have in my current boot drive. I'm more worried about
writing too much to the SSD. My understanding is that SSD's wear down
with too much writing to them. Thunderbird and the swapfile would be
some major recurring write events.

Yousuf Khan

 

[Yousuf Khan]

When it is said that they "are a good host" or "not so good", is that in
terms of performance, or longevity? I'd have thought that in terms of
performance, even if non-optimal, having almost any file on an SSD would
be better; but I could also believe that certain much-written files
would significantly shorted the life of the SSD, especially if not
optimised (is that what this "Trim" thing is about?).

Yeah, longevity is my major concern here too, so should I avoid putting
anything that has too much writing happening to it? As for Trim, it's a
command that tells the SSD that a sector is no longer in use, so it can
go in and erase that area during idle moments in the background.

Yousuf Khan

 

[Yousuf Khan]

Follow The Below Steps To Increase The Life of Your SSD Drives On
Windows 7

http://www.computerforums.org/forum...-life-your-ssd-drives-windows-7-a-208106.html


This guide is a year old so I would suggest reading as much as
possible from different authors.

Although there is some good info here, it sounds like he's just giving
general advice on how to improve Windows responsiveness. My
understanding is that SSD's are pretty sensitive to writes, but there's
never a problem with reading from an SSD. But this article seems to give
advice on how to minimize reads too.

Yousuf Khan

 

[J. P. Gilliver (John)]

Yeah, longevity is my major concern here too, so should I avoid putting
anything that has too much writing happening to it? As for Trim, it's a
command that tells the SSD that a sector is no longer in use, so it can
go in and erase that area during idle moments in the background.

Yousuf Khan

I'm not understanding what you mean by "erase" here. Are SSDs different
in some way, i. e. aren't bits erased anyway when overwritten?

 

[Dave-UK]

No, I'm not worried about space, I bought one big enough to accommodate
everything that I have in my current boot drive. I'm more worried about
writing too much to the SSD. My understanding is that SSD's wear down
with too much writing to them. Thunderbird and the swapfile would be
some major recurring write events.

Yousuf Khan

I think you are worrying too much about wear and tear on an SSD.
This will tell you how long you've got left.
(There's a free or pro version)
http://www.ssd-life.com/

 

[J. P. Gilliver (John)]

I think you are worrying too much about wear and tear on an SSD.
This will tell you how long you've got left.
(There's a free or pro version)
http://www.ssd-life.com/

Interesting. Two things I note from that site:1. The software (ssd-life) doesn't actually do any tests; it just
reports SMART data from the drive in a friendly way (including making
note if you run it two or more times and predicting a life from that).2. I hope I've got this wrong, but it seems to imply that once an SSD
has reached the end of its life, which seems to be decided _by the SSD
itself_, it switches to read-only.Oh, and a third thing: individual cells can be written to about ...
originally, 10,000 times; recently revised down to 5,000. With the wear
levelling that's (I think) built into the drive's hardware (more likely
firmware), this translates to 20G writes a day for 5 years for some
Intel drive (it gives the model number but not what size it is).

It seems to me, though, that as SSDs become more common, there needs to
be a tweak to OSs, such that frequently-written files - the registry,
page files, etc. - are treated differently by the OS. (Though if SSDs
are expected to last five years, that'll probably not happen, as OS
manufacturers want us to replace the OS - and by extension the computer
- more often than that. But that's just me being cynical.) Actually, I
think this sort of behaviour - commonly-modified files being treated
differently - should have been around long ago anyway.

 

[Andy Burns]

individual cells can be written to about ...
originally, 10,000 times; recently revised down to 5,000. With the wear
levelling that's (I think) built into the drive's hardware (more likely
firmware), this translates to 20G writes a day for 5 years for some
Intel drive (it gives the model number but not what size it is).

As long as three years ago, Intel were guaranteeing that their SSDs
would last 5 years with 100GB of writes/day, the endurance of each cell
does reduce each time they switch down to smaller die sizes, but the
capacity goes up faster than the endurance goes down, so with wear
levelling, there is still an overall win.

 

[dweebken]

My ssd scores a 7.2

My SSD scores 7.5 on a laptop on the WEI.

 

[Allen Drake]

Although there is some good info here, it sounds like he's just giving
general advice on how to improve Windows responsiveness. My
understanding is that SSD's are pretty sensitive to writes, but there's
never a problem with reading from an SSD. But this article seems to give
advice on how to minimize reads too.

Yousuf Khan

I think at this early stage everything that is out there is mostly
speculation and simply conversations. It seems that using multiple
drives would be good plan in any event. I have always had external
drives attached for files I rarely use and a small fast drive for
system files. I have also read that when an SSD fails it will only be
readable which is fine with me. If an HDD fails most of the time you
are completely unable to access the files. Also I have seen some
compare the SSD to a flash drive that has lasted far longer then any
HDD that has been accessed as many times. It seems that a good backup
plan is always the bottom line. Using motherboards that has SATA III
speeds will also be a good idea. I just bought a Crucial Adrenaline
Solid State Cashe
http://www.crucial.com/store/ssc.aspx?gclid=CJ_Y-vqggq8CFcRM4AodDm7y0A&cpe=pd_google_us

This might actually be a better choice than a stand alone SSD.

 

[Paul]

I'm not understanding what you mean by "erase" here. Are SSDs different
in some way, i. e. aren't bits erased anyway when overwritten?

In flash, a block consists of perhaps 64 pages.

Erasure (i.e. preparing for write) is done on blocks. The entire
block is erased. But you can write new data into a freshly erased
block, in units of pages. A page might be 2KB, a block 128KB, so
there are 64 pages per block. Page size and block size change
as the flash gets smaller geometry cells and higher chip densities.

The drive works most efficiently, if you need to write block-sized
things. Writing "small things", smaller than the block size, leads
to "write amplification". Write amplification refers to needing to
erase and rewrite major portions of a block. This article has some
nice pictures, showing how the SSD controller works behind the
scenes, to get the best usage from the flash.

http://en.wikipedia.org/wiki/Write_amplification

Paul

 

[J. P. Gilliver (John)]

J. P. Gilliver (John) wrote: []

I'm not understanding what you mean by "erase" here. Are SSDs different
in some way, i. e. aren't bits erased anyway when overwritten?

Having read further - the answer to my question is yes. Writing can only
be done to erased blocks, unlike in a conventional drive; thus when
files are erased (or rewritten, meaning the old data is erased), in an
SSD the controller has to go around afterwards actually erasing - it's
not just a matter of modifying the directory file. (Directory files
themselves have to be treated in this manner too.)
[]

The drive works most efficiently, if you need to write block-sized
things. Writing "small things", smaller than the block size, leads
to "write amplification". Write amplification refers to needing to

I suppose we're stuck with it now, but whoever invented that phrase
should be ...

erase and rewrite major portions of a block. This article has some
nice pictures, showing how the SSD controller works behind the
scenes, to get the best usage from the flash.

http://en.wikipedia.org/wiki/Write_amplification

[]

 

[Tom Del Rosso]

You can simply clone your system drive as I did at first when I
upgraded all my systems but that is not always the best option. You
need to know about SSD partition alignment
http://www.sevenforums.com/tutorials/113967-ssd-alignment.html

http://www.sevenforums.com/tutorials/70822-ssd-tweaks-optimizations-windows-7-a.html

Cloning can create a new partition instead of using the existing one,
depending on what cloning tool you use.

 

[Paul]

I suppose we're stuck with it now, but whoever invented that phrase
should be ...

Write amplification covers the situation where a portion of a block
needs to be copied to a new block, because the block erasure operation
would take out both unused space, and space that is still used.
It's effectively read-modify-write, but using a new block that may
have been erased when the drive was quiet. By keeping a pool of
erased blocks, you don't have to pay for the erasure delay
while a sustained copy is taking place. If you'd used up all the
erased blocks, then you'd have to erase some while attempting to
complete a transfer.

Paul

 

[Allen Drake]

Cloning can create a new partition instead of using the existing one,
depending on what cloning tool you use.

Exactly and depending on how you have that application set up. All in
all I have been satisfied with the speed of my SSDs as I gradually
replaced the HDDs and had no idea of the alignment issue until I
stumbled on some threads related to that subject. I plan on a clean
install of Windows 7 to new SSDs sometime soon. That will take care
of any misalignment.
The biggest gain I see in speed are the systems that actually have
SATA III motherboards.

 

[Loren Pechtel]

1. The software (ssd-life) doesn't actually do any tests; it just
reports SMART data from the drive in a friendly way (including making
note if you run it two or more times and predicting a life from that).

I don't think it needs two or more times, it's just a simple
extrapolation of life used vs time in service.

2. I hope I've got this wrong, but it seems to imply that once an SSD
has reached the end of its life, which seems to be decided _by the SSD
itself_, it switches to read-only.

Yup. When it considers all sectors to have reached their write limit
is no longer has anyplace to write to and it becomes read only.

 

[Loren Pechtel]

In

What are you using that tells you what the wear level is?

SSD-Life.