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Old 06-20-2009, 05:50 AM
BillW50
Newsgroup Contributor
 
Posts: n/a
Re: Questions with SSD drives

In
news:39a6bb75-f5dd-4816-a21c-aac61cc52d7a@y10g2000prc.googlegroups.com,
Roy typed on Fri, 19 Jun 2009 15:52:22 -0700 (PDT):
> On Jun 20, 2:09 am, "BillW50" <Bill...@aol.kom> wrote:
>>

Innews:d2e54351-eee5-49ff-b1ca-6168514fa4af@u10g2000vbd.googlegroups.com
,
>> Roy typed on Fri, 19 Jun 2009 04:42:48 -0700 (PDT):
>>
>>> On Jun 11, 8:39 am, "BillW50" <bill...@aol.kom> wrote:
>>>> Got me there Roy. I never tried that.

>>
>>>> Bill

>>
>>> Sorry Bill, just my keen interest to know how far with the SSD could
>>> go with regards to performance.
>>> Anyway I am looking forward in getting a core i7 run, triple
>>> channel RAM ,desktop replacement system by the end of the year with
>>> one SSD among the hard drives.....
>>> Regards
>>> Roy

>>
>> Remember there are fast SSDs and slow SSDs, just like HDD Roy. So
>> choose carefully. I am also thinking of upgrading one of my 702G8
>> with a 16G SSD. I don't need one that big yet, but I am curious to
>> play with one. Although it seems the SLC types are quickly being
>> replaced with the MLC types.
>>
>> Bill

>
> Huh? really...could you please tell me about it...
> I thought that in solid state structure everything is simplified<grin>
> Never did thought about the SLC and MLC, .....
> Could you please elaborate .....


http://www.storagesearch.com/ssd-slc-mlc-notes.html

Basically, SLC stores 2 bits per cell, while MLC stores 4 bits per cell.
A MLC costs half as much as a SLC is to produce. So what's the downside
of MLC?

Their lifespan is a tenth of SLC types. Also an area has to be erased
first before it can be written too with MLC types. So at first, your MLC
can appear very fast. As all areas has been erased already. And writing
to the MLC, will use up all of the erased areas first. Thus the speed is
doing quite well right now.

But at some point, all previously erased areas will be all gone. Now
before a write, it must now do an erase cycle before any new writes. Now
the write speed of the MLC type goes down the tubes. As your write speed
can be halved or even far worse.

You would think they would have the controllers busy using the erase
cycle during idle times to make more quickly writable areas. But they
just don't do this as far as I know. Thus you can avoid all of this by
getting SLC types. But SLC types are quickly disappearing and are being
replaced by the cheaper MLC types. Worse, the manufactures are now
hiding whether it is a MLC or not. <sigh>

--
Bill
Windows 2000 SP4
Asus EEE PC 701G4 ~ 2GB RAM ~ 16GB-SDHC


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Old 06-20-2009, 05:50 AM