Samsung 845DC EVO SSD Review: 3-Bit MLC Hits The Enterprise

Results: Performance Consistency

We also pay a lot of attention to the performance consistency of enterprise-class SSDs. This is what separates a good drive from a great one when all of the corner case testing appears equal. Viewing the data with more granularity gives us insight on particular drive behaviors.

For the following tests, Samsung's 845DC EVO and three comparison SSDs are subjected to 25 hours of continuous random 4 KB writes. We record IOPS every second, giving us 90,000 data points. We then zoom in to the last 60 minutes to more coherently visualize the results.

The 845DC EVO demonstrates good consistency in our latency tests, surpassing Intel's SSD DC S3500 and Samsung's own SM843. It isn't able to keep pace with Micron's M500DC, which is still a steal considering $/IOPS. 

Samsung can be proud that more than 98% of all 1 s averages are better than the 14,000 IOPS specification. In fact, the lowest 1 s average is over 13,000 IOPS, which is still good for this market segment.

The histogram shows us a clean distribution without any major outliers. In this view, we see that the data points form an almost perfect bell curve, with the overall average latency contained within the largest bin of the histogram.

Looking at the first nine hours of write testing shows us that the 240 and 960 GB models perform similarly. You can see the effect of having more available NAND for over-provisioning, though. The 240 GB model exits its fresh-out-of-box condition and enters steady-state much more quickly than the 960 GB model. In fact, that latter implementation doesn't hit steady state until 12 hours after we begin the tests.

I also observed that, during the first 50 minutes, while still in the fresh out of box state, Samsung's 845DC EVO hit an incredibly stable 80,000 IOPS.

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  • So basicly it's the more durable version of the 840 evo much like opertons and xeons are to the FX and core i7 series.
    3
  • like we know now after the ssd endurance test samsung is the worst enterprise candidate.
    -8
  • 409959 said:
    So basicly it's the more durable version of the 840 evo much like opertons and xeons are to the FX and core i7 series.


    Yes, that's a fair analogy. Just like the Xeon E3-1275v3 is an i7-4770K, but with ECC support.
    3
  • I've yet to see an SSD fail due to read/write endurance. I only see them fail when the controller gets bugged, which seems to happen all the time, especially on loss of power.
    2
  • I'm guessing this SSD doesn't have to new firmware code that extends life and speed.
    0
  • Another win for the EVO. This SSD modified for enterprise workloads makes it a good buy for webservers.

    Hopefully the price will go down after launch, and then I see this being the best choice of webhosts.

    Cheaper and adequate for that workload.
    0
  • Eh I'll keep my 840 EVO 250GB
    0
  • "Even still, I wand to commend Samsung's execution." (last page 1st paragraph) I guess that is supposed to be want, unless Drew Riley has become a wizard now :D
    0
  • Commending their execution would be a bit harsh, don't you think?
    0
  • 885869 said:
    Commending their execution would be a bit harsh, don't you think?


    I'm sure worse things were said about Samsung at WWDC '14 yesterday ;)
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  • 1670073 said:
    "Even still, I wand to commend Samsung's execution." (last page 1st paragraph) I guess that is supposed to be want, unless Drew Riley has become a wizard now :D


    Now that you mention it.....
    0
  • 4KB random write, and average response time.

    Nuff said.

    You'd have to be out your mind to put TLC in a a critical environment.
    -1
  • @eriko everyone's critical environments need a little tender loving care
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  • The 845dc isn't necessarily the "worst enterprise candidate"; for one thing it wasn't the bottom in every test.

    For another, it's more about VALUE and that's the main point of the article. I assume the top SSD's in this category were MLC not TLC and also more expensive.
    1