<div dir="ltr"><div class="gmail_default" style="font-family:trebuchet ms,sans-serif">Thats some interesting information on SSD's :-)</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Feb 29, 2016 at 10:18 AM, Carruth, Rusty <span dir="ltr"><<a href="mailto:Rusty.Carruth@smartm.com" target="_blank">Rusty.Carruth@smartm.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">There are a few secrets for longevity on an SSD.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">One way, as Stephen notes, is reducing your writes (trim also helps with this, by the way).<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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
<b>may</b> 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.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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)
<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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 ;-)).<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">So a single 512-byte write resulted in 100Kbytes (or whatever) being written to the flash!<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">So, a single write was amplified into what looked more like 200 writes! Ouch! Welcome to write amplification!<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">(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!)<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">Now, a little bit more info about SSDs, followed by 2 disclaimers.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">SSDs are made up of Flash. Flash comes in at least 3 varieties:<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">SLC – aka ‘Single Level Cell’, which means that you only store 1 bit per transistor cell<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">MLC – aka ‘Multi Level Cell’, which means you store 2 bits per transistor cell.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">TLC – aka ‘Triple Level Cell’, which means (you probably guessed it) that you store 3 bits per transistor cell.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">(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’!)<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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:<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">SLC: 100,000<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">MLC: 10,000<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">TLC: 1,000 (I think – its been a while since anybody mentioned this number to me)<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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
</span><span style="font-size:10.0pt;font-family:Wingdings;color:#1f497d">J</span><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">).<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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!!!)<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">Disclaimer 1 – I work for a company that makes SSDs. The above is NOT professional advice. See a real SSD shrink for professional advice.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">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.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d">Rusty<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:plug-discuss-bounces@lists.phxlinux.org" target="_blank">plug-discuss-bounces@lists.phxlinux.org</a> [mailto:<a href="mailto:plug-discuss-bounces@lists.phxlinux.org" target="_blank">plug-discuss-bounces@lists.phxlinux.org</a>]
<b>On Behalf Of </b>Stephen Partington<br>
<b>Sent:</b> Monday, February 29, 2016 9:45 AM<br>
<b>To:</b> Main PLUG discussion list<br>
<b>Subject:</b> Re: Upgrade old laptop with SSD<u></u><u></u></span></p><div><div class="h5">
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<p class="MsoNormal"><span style="font-family:"Trebuchet MS","sans-serif"">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.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:"Trebuchet MS","sans-serif"">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).<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:"Trebuchet MS","sans-serif"">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).<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:"Trebuchet MS","sans-serif"">With an SSD the general user experience will be pretty good, but Anytime you run updates it will still crawl, regardless fo the SSD :-)<u></u><u></u></span></p>
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<p class="MsoNormal">On Mon, Feb 29, 2016 at 8:49 AM, Keith Smith <<a href="mailto:techlists@phpcoderusa.com" target="_blank">techlists@phpcoderusa.com</a>> wrote:<u></u><u></u></p>
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Hi,<br>
<br>
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.<br>
<br>
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).<br>
<br>
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.<br>
<br>
Newegg is selling a 240G Kingston SSD for $65 which is probably way more storage than I would ever need.
<a href="http://www.newegg.com/Product/Product.aspx?Item=N82E16820721108" target="_blank">
http://www.newegg.com/Product/Product.aspx?Item=N82E16820721108</a><br>
<br>
What type of lifespan should I expect for an SSD with moderate usage?<br>
<br>
Anything specific I should be looking at?<br>
<br>
Thank you so much for your help!!<span style="color:#888888"><br>
<br>
<span>-- </span><br>
<span>Keith Smith</span><br>
<span>---------------------------------------------------</span><br>
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<p class="MsoNormal">-- <u></u><u></u></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">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.<br>
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Stephen<u></u><u></u></p>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature">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.<br><br>Stephen<br><br></div>
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