<div dir="ltr"><br><div class="gmail_extra"><br><br><div class="gmail_quote">On Sun, Mar 17, 2013 at 9:24 AM, Matt Simmons <span dir="ltr"><<a href="mailto:standalone.sysadmin@gmail.com" target="_blank">standalone.sysadmin@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">There are a lot.<br>
<br>
First, lets talk about what they have in common.<br>
<br>
Both use flash memory.<br>
<br>
OK, now lets talk about the differences.<br></blockquote><div> </div><div>...</div><div><br></div><div style>Really interesting stuff, thanks for the insight! Definitely have a much better understanding of how an SSD actually works and what makes it different than what we're used to thinking about in terms of storage.</div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Another big factor is data retention.The underlying way that flash<br>
memory writes is essentially to put an electrical charge into a small<br>
deposit of doped silicon. Over time (months typically), if left<br>
unrefreshed, that electrical charge will dissipate and the controller<br>
won't be able to determine whether the bit is a one or a zero. For<br>
this reason, SSD controllers periodically go through the old data and<br>
"scrub" it, refreshing the electrical charge. This is really hard to<br>
do if the flash chip is on a USB keychain in your backpack.<br></blockquote><div><br></div><div style>Hmm. Interesting. So would a logical conclusion to this be that archival storage on an SSD is not recommended? As in, for example, don't stick an ssd into an external storage bay, throw it in the closet and expect the data to be readable in a year? Also, don't stick an ssd into a system that you only use (and then power down) a couple of times/month (or less frequently)? Basically - the SSD needs power.</div>
<div style><br></div><div style>This is definitely one area of SSD storage theory that I was completely unaware of.</div><div style><br></div><div style>Several folks that I've talked to have said that they install their OS and programs onto their SSD and put everything else onto spinny storage (what is the right term to reference a spinning disk to differentiate it from an SSD?). I bought an SSD to take a completely different approach - I left my OS, applications, etc where they were. I use the SSD as a sort of temporary storage for my Adobe Premiere video editing projects. Once the project has been completed and delivered to the client, I move it to "permanent" storage on the spinning disk. Outside of nonsense I've dealt with for many, many years with Premiere, as has traditionally been the case, disk i/o seems to be the biggest bottleneck with today's multi-processor, multi-core, 10+ gigs of memory systems.</div>
<div style><br></div><div style>It seems like by putting the OS on your SSD, you get a sort of narrow benefit - most of the libraries are loaded into memory on boot and obviously are never written to during the normal course of operations. Most of your performance advantage is then at boot time, and you're back to the slower read/write times thereafter. Obviously, I'm using mine for a pretty narrow case as well, but I've also got a very specific use case in mind.</div>
<div style><br></div><div style>How are others taking advantage of the SSD performance? I assume that most of us either have an SSD in our laptops or are mixing them with spinning disks in desktop systems.</div><div style>
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