Re: Upgrade old laptop with SSD

Thats some interesting information on SSD's :-)

On Mon, Feb 29, 2016 at 10:18 AM, Carruth, Rusty <Rusty.Carruth@smartm.com>
wrote:

> There are a few secrets for longevity on an SSD.
>
>
>
> One way, as Stephen notes, is reducing your writes (trim also helps with
> this, by the way).
>
>
>
> Another way is to not use the whole drive. That is, don’t fill it up.
> That effectively gives you more ‘spares’ so that the drive *may* be able
> to reduce the ‘write amplification’ a little, and also perhaps have
> somewhere to write stuff even if the number of ‘bad blocks’ (for a fuller
> drive) would make the drive unusable.
>
>
>
> Huh? What is ‘write amplification’? Well, it’s a ‘feature’ of SSDs
> caused (primarily) by the fact that the SSD is not arranged as LBAs
> (sectors). The smallest amount of the flash that can be erased is an erase
> block, which can be 1Mbit or more! And the smallest amount you can write
> is a ‘page’. (Pages tend to be 4k Bytes or more)
>
>
>
> And you cannot write to an un-erased area – that is, once written a ‘page’
> in the erase block, you cannot write it again without erasing first.
>
>
>
> So, imagine you are filling up an erase block with sectors (512 bytes).
> Now lets say you have sectors 1-20 and 2000-2010 in it, and now its full.
> Now, you change what’s in sector 2000 and write it back.
>
>
>
> The drive CANNOT write it back in that erase block (unless there is space
> at the end of the erase block, but then I just said it was full ;-)).
>
>
>
> So, it has to ‘do something’ with that new sector. Sometimes it has to
> COPY the ENTIRE erase block into a NEW erase block, inserting the new
> sector’s worth of data.
>
>
>
> So a single 512-byte write resulted in 100Kbytes (or whatever) being
> written to the flash!
>
>
>
> So, a single write was amplified into what looked more like 200 writes!
> Ouch! Welcome to write amplification!
>
>
>
> (And it gets even worse if there aren’t enough ‘spare’ (already erased but
> not written) blocks – you may have to copy other full or partially-full
> blocks around also!)
>
>
>
> For some drives, they can do a better job if they have more spare blocks
> around – so, if your drive isn’t full you’ve got more spares (if the drive
> firmware views them that way). In addition, you may be able to run longer
> by having more bad blocks but not enough to have no non-bad blocks for the
> amount of data you have on the drive.
>
>
>
> Now, a little bit more info about SSDs, followed by 2 disclaimers.
>
>
>
> SSDs are made up of Flash. Flash comes in at least 3 varieties:
>
>
>
> SLC – aka ‘Single Level Cell’, which means that you only store 1 bit per
> transistor cell
>
> MLC – aka ‘Multi Level Cell’, which means you store 2 bits per transistor
> cell.
>
> TLC – aka ‘Triple Level Cell’, which means (you probably guessed it) that
> you store 3 bits per transistor cell.
>
>
>
> (As a very scary fact, my understanding is that a transistor cell holds,
> at maximum, about 100 electrons. So, for SLC there are 2 values
> represented by 0 to 100 electrons. (you can pretend that under 50 electrons
> means a zero and above that means a 1 and not be too far off the mark).
> For MLC, 4 values are represented by those same 100 electrons. For TLC,
> that’s 8 values, or a difference of only 100/8 electrons per different
> ‘value’!)
>
>
>
> Now, the other critical thing is that Flash manufacturers ‘guarantee’ a
> maximum error rate across the entire chip until that chip reaches a certain
> number of ‘program/erase’ cycles (as described above). It is true that
> some chips will do MUCH better (We’ve seen, in our testing, an SLC chip run
> 1million P/E cycles before becoming unusable – when the factory only gives
> 100,000). But in any case, here’s my understanding of the PE numbers for
> the different technologies:
>
>
>
> SLC: 100,000
>
> MLC: 10,000
>
> TLC: 1,000 (I think – its been a while since anybody mentioned this
> number to me)
>
>
>
> Which speaks directly to Stephen’s comment about number of PE cycles (ok,
> he didn’t say PE, but that’s what he is actually referring to J).
>
>
>
> However, you probably don’t want to seriously consider rushing out and
> buying SLC drives – they cost MUCH more than MLC drives (like, 10 to 100
> times more). Just back up early, back up often (as you should do for ANY
> primary storage device!!!)
>
>
>
>
>
> Disclaimer 1 – I work for a company that makes SSDs. The above is NOT
> professional advice. See a real SSD shrink for professional advice.
>
>
>
> Disclaimer 2 – Due to our IT department’s method of handling email, at
> this time I can RECEIVE PLUG emails, but I cannot REPLY to them (and have
> them seen). So I’m BCC’ing people and hoping they reply all, so that you
> can see this. Otherwise, only 2 folks will read it.
>
>
>
> Rusty
>
>
>
> *From:* plug-discuss-bounces@lists.phxlinux.org [mailto:
> plug-discuss-bounces@lists.phxlinux.org] *On Behalf Of *Stephen Partington
> *Sent:* Monday, February 29, 2016 9:45 AM
> *To:* Main PLUG discussion list
> *Subject:* Re: Upgrade old laptop with SSD
>
>
>
> The lifespan will depend entirely on the number of Writes the drive will
> incur. The first thing you want to do once the Os is installed is to reduce
> this. If you have enough ram and are comfortable with nos wap go for it. If
> you want the backup i would suggest pushing swappiness all the way over so
> that it is used only if there is no ram.
>
>
>
> Most SSD's will give you a 3 year warranty. Samsung with their Evo 850
> drives and the new vnand are offering 5 year warranty. (they are also
> wicked fast).
>
>
>
> That being said. with minimal writes I have seen older SSD's last for much
> longer than their supplied 3 year warranty (I have one that is pushing 6
> right now).
>
>
>
> With an SSD the general user experience will be pretty good, but Anytime
> you run updates it will still crawl, regardless fo the SSD :-)
>
>
>
> On Mon, Feb 29, 2016 at 8:49 AM, Keith Smith <techlists@phpcoderusa.com>
> wrote:
>
>
>
> Hi,
>
> I have an older laptop. Not sure when I bought it. I'm thinking I bought
> it before 2009, however the CPU is an AMD 3300M which according to what I
> am reading was not in production until 2011. It has 4G of RAM and a 500GB
> HD. It's running Win7, which is a little slow.
>
> I was thinking of replacing the HD with an SSD and potentially making it
> into a "Chromebook".... (Thunderbird/Libre Office/ Chrome Browser) I'm
> reading the SSD's are 10x faster than the HD. There has been prior
> discussions about breathing life into old hardware by replacing the HD with
> SSD and installing Linux (now we are on topic).
>
> Initially I was thinking a small SSD since I will probably never use this
> laptop in production... But you never know. If these mods work out I might
> dual boot it - Win7 / Mint 17 KDE.
>
> Newegg is selling a 240G Kingston SSD for $65 which is probably way more
> storage than I would ever need.
> http://www.newegg.com/Product/Product.aspx?Item=N82E16820721108
>
> What type of lifespan should I expect for an SSD with moderate usage?
>
> Anything specific I should be looking at?
>
> Thank you so much for your help!!
>
> --
> Keith Smith
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>
>
>
>
> --
>
> A mouse trap, placed on top of your alarm clock, will prevent you from
> rolling over and going back to sleep after you hit the snooze button.
>
> Stephen
>



--
A mouse trap, placed on top of your alarm clock, will prevent you from
rolling over and going back to sleep after you hit the snooze button.

Stephen
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