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I work for a nonprofit organization that contracts with a local IT outfit. We are currently using three enterprise SSD drives in our Dell PowerEdge R820 rig, set up in a RAID 5 configuration. We have been having discussions about upping our capacity to at least 1 TB (possibly 2 TB), because we always seem to be up against our capacity limit as things stand now.

The contracted IT outfit has recommended three Samsung SM863 SATA 1.92TB (Enterprise) drives to replace the current drives. Their cost on the drives was going to bring our total to around $6,000 (not including labor). Of course, you can buy these drives direct from Samsung for $1,260. This is where my mistrust of this recommendation began to grow, as a $1,000 price difference from OEM versus the IT outfit is very odd to say the least.

I've done a bit of research and found that when it comes to solid state, the enterprise drives have about the same median lifespan as the consumer level drives, like the Samsung EVO 850 1TB, which sell for considerably less money (around $300 each) or Samsung PRO 850 1TB ($400). The median lifespan on the 850 EVO 1.5 million hours versus the enterprise level, which are 2 million hours. The 850 PRO has 2 million hours.

These are a few of the articles I found about Enterprise versus Consumer:

https://www.backblaze.com/blog/enterprise-drive-reliability/

http://www.computerworld.com/article/2687068/consumer-drives-shown-to-be-more-reliable-than-enterprise-drives.html

The guy we contract with for IT is totally against using anything less than Enterprise-level drives in our server. We currently have about 30 computers in our facility that are connected to the server at any given time.

My question is, what should we as a non-profit do in this situation? We have the ultimate authority over what hardware we use because we own the server. Should we go against the advice of our contracted tech and go with EVO or PRO drives or will we regret it down the line?

Given the price differences, we CAN afford to keep a couple of EVO or PRO drives as backup in case the drives fail. We could NOT do that with the Enterprise drives (if we can afford them at all), since they are $1,200 each.

We can buy any of the drives direct from Samsung and get the OEM warranty of three years for EVO or 10 years for PRO that come with them, too.

JustAnotherKnowItAll
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  • I'm kind of leaning more now toward the 850 PRO drives, as they have a 10 year warranty and are guaranteed to withstand 150TB in writes minimum. I've read about them getting much more than that, though. The 150TB in writes is the most conservative number provided by Samsung. – JustAnotherKnowItAll Mar 16 '16 at 17:34
  • Katherine Villyard: I actually read that forum post, but it seemed there was disagreement among those that answered. Those articles dealt with the 840 line of products versus Enterprise. My understanding is the 850 PRO can withstand 150TB minimum in writes. Considering that we are always at capacity on our server but have managed to stay within the 300 GB limit, I see it taking a very long for us to write 150TB on a PRO drive. – JustAnotherKnowItAll Mar 16 '16 at 17:41
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    There is one other point that needs ti be considered - does Dell certify the R820 with the drives you want to use? If not you are putting your server in unsupported territory. Also as another non profit tech I've bought enterprise parts on Amazon for years. – Tim Brigham Mar 16 '16 at 19:42

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On paper, enterprise SSD drives have the following advantage over regular consumer drives:

  • better validated firmware
  • better guaranteed write endurance
  • power loss protected DRAM cache

When compared to quality consumer drivers (Samsung 850 PRO, Crucial M500/M550/M600, ecc.), the only really important thing is the write protected DRAM cache. SSDs really need a very fast, local DRAM cache to shine, and using a protected cache permits to leave it enabled without fear of data loss.

If your RAID controller can use non-certified drives leaving enabled the disk's DRAM cache, consumer driver are a tempting option. However, read here also to have a better understanding of what this implies.

Anyway, before completely ruling out enterprise SSDs, give a look at the relatively cheap Micron M510DC or Samsung own PM863. They are enterprise drives, but at a (relatively) lower cost.

Community
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shodanshok
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Given that you said it's not feasible to keep spare Enterprise drives around, I'd say that going for the consumer drives (that is, the Samsung EVO or PRO SSDs) is a better call, since you lose all remaining redundancy in RAID 5 when you lose a disk. And having to wait for a new drive to show up means that you're running the risk of total data loss if another disk has an issue before the array can be rebuild. So keeping the spare drives on hand is a good call.

Also, what's the reason for using RAID5? It's performance is pretty awful on writes, and though the SSD will make up for some of that, I'd go for RAID1 or 10 unless you absolutely need to maximize the usable space on 3 drives.

zymhan
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  • I said it wouldn't be feasible to keep the more expensive Enterprise SSDs around to use in case of failure, due to the $1,200 cost on each of them. The 850 Pros we could definitely afford to keep a couple of extras around. The harddrive controller I have confirmed will work with the 850 Pros, as well. Knowing this, would it change your mind? It is configured RAID5 because we don't want to add the cost of a fourth drive into the mix. We are a nonprofit and are trying to keep costs down. We do have an offsite backup, too. – JustAnotherKnowItAll Mar 16 '16 at 18:53
  • Gotcha. You could also mirror two larger drives instead of using RAID5 across three smaller ones. But I'll stop hounding you on that :) Sorry if I didn't make it clear, I think the 850 Pros or 850 Evos are a good call. Pros if you can afford it. – zymhan Mar 18 '16 at 14:53