Samsung SSD 845DC EVO/PRO Performance Preview & Exploring IOPS Consistency

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• hojnikb - Wednesday, September 3, 2014 - link

  Looks like, they ain't doing Turbowrite on TLC models :)

• Kristian Vättö - Wednesday, September 3, 2014 - link

  TurboWrite wouldn't make any sense on an enterprise drive because all that matters is sustained performance. Client drives are a different case because IO activity tends to happen in bursts, so having a fast buffer is beneficial (and it makes the drive look better in benchmarks).

• hojnikb - Wednesday, September 3, 2014 - link

  Yeah i figured as much. Aside from being more suited for short bursts (as you'd said) its really great for marketing department, since they can slap magical 500MB/s+ speeds, that every uninformed buyer is after. 500MB/s sure sells a lot better than 250MB/s (or even less, if we're dealing with lower capacities) :)

• Spirall - Wednesday, September 3, 2014 - link

  Thanks for the article. Would suggest to make a $/manufacturer declared write endurance comparison (PB writen until manufacturer write warranty end). If there's a chance (due to the difficult on testing time) also make a $/tested write life (PB writen until tested dead).

• Kristian Vättö - Wednesday, September 3, 2014 - link

  $/endurance is certainly something I will be looking at in the future. This was more of a preview than a full review and in the full review I will have more graphs and comparisons to support the conclusions :)
  
  As for actual endurance testing, that is something I will not do. It took me two weeks of continuos writing to get the rated endurance to drop by 1% in the 845DC PRO, so it would take way too long to wait for the drive to die.

• hojnikb - Wednesday, September 3, 2014 - link

  And there is a good chance, that thing would still go strong after rated endurance would drop to 0% (unless its hardcapped to die after that).

• Essence_of_War - Wednesday, September 3, 2014 - link

  Another excellent article, Kristian.
  
  A question/comment, though, do you think it would make more sense to report the stdev measurements as an "error bar" attached to each data point rather than an additional graph with a 2nd y-axis? I think that might be more compact without having to worry about having multiple y-scales to read. Then it might even be possible to plot an average + error bars data set for multiple different SSDs on the same axis w/o having to worry about which curve is the avg, which curve is the stdev, etc.

• hulu - Wednesday, September 3, 2014 - link

  Another way to present the standard deviation data would be to draw it in two average +/- stdev graphs above and below the average graph. This would better allow visualizing the actual values the average minus stdev has.

• Kristian Vättö - Thursday, September 4, 2014 - link

  Thanks for the suggestion. I will certainly look into alternative ways to present the standard deviation. I need to redo the graphs anyway for our new suite, so while I'm at it I can see if there is a better way to present the data.

• Essence_of_War - Thursday, September 4, 2014 - link

  Best luck then, I'm sure you'll figure out a good way to do it.