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
Comments Locked


View All Comments

  • Bleakwise - Sunday, April 24, 2016 - link

    I apologize for being rude but that's just not what they are made for. Paying 1,000$ for a 2tb NVME SSD just for cold storage is a lot like buying a 500,000$ super-car just to drop your kids off at school....
  • Bleakwise - Sunday, April 24, 2016 - link

    More like even up to 8k.

    A mechanical hard drive will roll out 150-200 GigaBYTES per second sequential read. 4k video is like 5 megaBYTES per second max. 8k would be 20, 16k would be 80. This is on h264, h265 will cut these in half, so you could watch a 32k video on something like a WD black.

    I suppose if you wanted to play back something in 64k resolution you'd need an SSD though, at least until CPU/GPU tech makes h266 or h267 codec or whatever available.
  • Bleakwise - Sunday, April 24, 2016 - link

    To be clear. The only reason content creators need NVME drives for 4k is because they work in uncompressed or intermediate formats. They need NVME drives for the same reason that a 4k bitmap is like 22 megabytes while the JPEG is just one or two.
  • Eden-K121D - Sunday, April 24, 2016 - link

    I think You meant MegaBYTES otherwise your hypothetical disk would be faster than anything on this planet LOL
  • slowdemon21 - Friday, April 29, 2016 - link

    SeaGate barracuda 195 MegaBytes per sec
  • BrokenCrayons - Friday, April 22, 2016 - link

    Between the OS and software, my Windows desktop is currently using about 110GB of a 250GB hard drive. I don't game much, but there are handful of titles loaded on that system and I haven't exactly been working very hard at keeping my drive clean.

    On my primary computer (the desktop is more a network appliance than a day-to-day workstation as it runs headless now thanks to a combination of Steam in home streaming and VNC), a laptop with a 60GB SSD, there's about 35GB of free storage capacity, but the OS footprint is a lot smaller since it's a Linux box.

    Granted, games are getting larger and a few newer titles I'm likely to play in the next year or so will make it necessary to start looking at more storage, but 250GB seems perfectly reasonable right now.
  • jabber - Friday, April 22, 2016 - link

    Yeah just running 80GB of the 250GB 850EVO in my workstation. Having masses of software and data hanging around on a mchine seem crazy to me. Each to their own. However, most customers I see struggle to go over 60-70GB.
  • bji - Friday, April 22, 2016 - link

    This is because you guys don't pirate tons of movies and hoard them on SSD drives like some people who then complain about the cost of the media they use to store their pirated goods. I don't either, which is why the 250 GB SSD in my macbook pro is still only half full after nearly 4 years of use.
  • bji - Friday, April 22, 2016 - link

    BTW complaining about the cost of storage for pirated goods is like the ultimate douchebaggery imagineable. Not only are you ripping off people who worked to create the content you've pirated, you want to complain about how much money you have to pay to companies to produce the storage that you need to store it.
  • StrangerGuy - Friday, April 22, 2016 - link

    That's not ultimate pirate douchebaggery, it would be complaining why pirated videos are no longer available in Xvid because everybody should cater to people with decade old DVD players.

Log in

Don't have an account? Sign up now