Performance Consistency

Our performance consistency test explores the extent to which a drive can reliably sustain performance during a long-duration random write test. Specifications for consumer drives typically list peak performance numbers only attainable in ideal conditions. The performance in a worst-case scenario can be drastically different as over the course of a long test drives can run out of spare area, have to start performing garbage collection, and sometimes even reach power or thermal limits.

In addition to an overall decline in performance, a long test can show patterns in how performance varies on shorter timescales. Some drives will exhibit very little variance in performance from second to second, while others will show massive drops in performance during each garbage collection cycle but otherwise maintain good performance, and others show constantly wide variance. If a drive periodically slows to hard drive levels of performance, it may feel slow to use even if its overall average performance is very high.

To maximally stress the drive's controller and force it to perform garbage collection and wear leveling, this test conducts 4kB random writes with a queue depth of 32. The drive is filled before the start of the test, and the test duration is one hour. Any spare area will be exhausted early in the test and by the end of the hour even the largest drives with the most overprovisioning will have reached a steady state. We use the last 400 seconds of the test to score the drive both on steady-state average writes per second and on its performance divided by the standard deviation.

Steady-State 4KB Random Write Performance

Starting with a look at steady-state performance, the 750 EVO is clearly inferior to the 850 EVO, particularly at 250GB. But it outperforms most of the planar TLC competition and the occasional low-end MLC drive.

Steady-State 4KB Random Write Consistency

The high consistency score is a hallmark of Samsung's top-notch controller architecture. The 750 EVO is in an entirely different league from the planar TLC drives.

IOPS over time
25% Over-Provisioning

The 750 EVO's initial burst of high performance is relatively short-lived, but it transitions into a very well-regulated steady state. The gradual performance recovery before a second smaller drop in performance is less pronounced than on the other Samsung drives, but is still present.

With extra overprovisioning, the 750 EVO's steady state shows much looser performance regulation but is still delivering a better worst-case than its competition's best-case.

Steady-State IOPS over time
25% Over-Provisioning

A closer look at the 750 EVO's steady state is pretty boring, with no clear patterns of periodic background maintenance or sporadic outliers.

Introduction, The Drive & The Test AnandTech Storage Bench - The Destroyer
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  • jabber - Friday, April 22, 2016 - link

    Yeah must admit I don't have the need or want to hoard masses of ripped off content. That is a psychosis I can do without. It just junk.
  • Deelron - Friday, April 22, 2016 - link

    My wife has 200 GB of Life Event Photos/Videos going back 20+ years (and I'd imagine people with much better cameras then we had could have significantly more, particularly if they have a larger family) and there's not a bit of media on the machine. After OS and regular applications the minimum suitable single drive would be 480 GB, without a lick of pirated media.
  • jabber - Saturday, April 23, 2016 - link

    Would that 200GB+ be better backed up safely somewhere than sitting on the main drive? Keeping masses of mainly dead/unused data on a day to day machine seems odd nowadays. There are systems better suited for that kind of data.
  • Deelron - Sunday, April 24, 2016 - link

    It's backed up locally (two he's that switch every month) and via cloud. It's not just "sitting" there any more then a physical photo album would be.
  • Margalus - Saturday, April 23, 2016 - link

    It has nothing to do with piracy.. My Steam folder alone is over 1GB.
  • erple2 - Saturday, April 23, 2016 - link

    I think that I have save games that are larger than 1GB.
  • Eden-K121D - Sunday, April 24, 2016 - link

    You mean 1TB
  • Margalus - Sunday, April 24, 2016 - link

    lol, yes. that is what I meant...
  • Lolimaster - Friday, April 22, 2016 - link

    It's simply because you didn't embrace internet. That kind of low storage needs is more of the pre-2000's.

    Between movies, tv series, some cartoons, anime, manga it's easy to need more than 1 6TB drive. I have 4x 6TB's right now.
  • jabber - Saturday, April 23, 2016 - link

    Yes but you appear to be 16 years aold. Some of us are over 30. If you are over 30 I see that as a cry for help.

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