On Mon, 29 Sep 2014 11:15:21 +0200 Emmanuel Lacour wrote: > On Mon, Sep 29, 2014 at 05:57:12PM +0900, Christian Balzer wrote: > > > > Given your SSDs, are they failing after more than 150TB have been > > written? > > between 30 and 40 TB ... > That's low. One wonders what is going on here, Samsung being overly optimistic or something else... OTOH, that is about the right amount of 40GB/day and THREE years, the warranty period.... > > > > > Thought, statistics gives 60GB (option 2) to 100 GB (option 1) writes > > > per day on SSD on a not really over loaded cluster. Samsung claims to > > > give 5 years warranty if under 40GB/day. Those numbers seems very > > > low to me. > > > > > This is confusing, as the Samsung homepage gives a 150TBW lifetime, and > > this would be about half of it. > > > > I didn't saw this spec. And did a quick look at samsung vs intel. Intel > s3500 120Go is 70TBW which is the same as 40GB/day for 5 years. > The 3500s are the "low end" models. ^o^ And you better believe that they will last that time. ^^ > > > > > If you read/search this ML it should be clear to you that the only SSDs > > that have the durability (and a good TBW/$ ratio when looking at it > > long term) are Intel DC 3700S. > > Monitor their wearout ratio and you're likely never have one fail on > > you unexpectedly. > > A 200 TB DC 3700S has a TBW of 1825, more than 10 times that of your > > Samsungs and would allow you to write 1TB each day for 5 years. > > > > > Yes, I did a quick compare just now: > > Brand Model TBW ? ?/TB > Intel S3500 120Go 70 122 1,74 > Intel S3500 240Go 140 225 1,60 > Intel S3700 100Go 1873 220 0,11 > Intel S3700 200Go 3737 400 0,10 > Samsung 840 pro 120Go 70 120 1,71 > > amazing! > > > considering that I need only 80Go, I can keep free space for > over-provisionning and thus the S3700 200Go may be the better choice in > ?/TB. > Over-provisioning helps as well, but it is not a necessity with those Intel SSDs. Note that in your particular configuration of having basically one SSD per HDD the 100GB DC S3700s are more than fast enough. Aside from the TBW/$ cost (which is of course based on current prices) one also has to consider the expected deployment duration. We do retire/recycle machines after 4-5 years, so for us anything that survives this time for sure is good enough. ^^ Christian -- Christian Balzer Network/Systems Engineer chibi at gol.com Global OnLine Japan/Fusion Communications http://www.gol.com/
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