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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  • lilmoe - Friday, April 22, 2016 - link

    Meh. I'll wait until it's half price.
  • haukionkannel - Friday, April 22, 2016 - link

    Well, this is 10$ cheaper that 850evo, so this will be very popular among system builders and other with tight budget. Normal upgrade user will definitely go for 850. But this is good enought to most customers.
  • Space Jam - Friday, April 22, 2016 - link

    $10 for considerably worse performance does not a winner make.

    I have a hard time swallowing the cheapo, terrible performance $60 TLC drives. If Sammy thinks anything more than $65 is a good price they have another thing coming.

    $60 for a budget 120GB SSD is some audacity.

    I and most others will stick to BX100s @ $70 and 850 EVOs @ $75 during the (frequent) sales.
  • jabber - Friday, April 22, 2016 - link

    And if it's upgrading a lot of the older machines desktops and laptops that still only run on SATA doesn't matter. As long as it pushes 285MBps (ish) all day that's all it needs. A lot of kit out there is still SATA II.
  • Alexvrb - Friday, April 22, 2016 - link

    Yeah it's got a sequential speed cap. Not all tasks are about peak speeds. I'm pretty sure in terms of IOPS a decent SSD will still beat the snot out of an OEM-grade penny-pinching budget model, even on old SATA 2. Which brings us back to the idea that this is for OEMs and builders - truly this is a "builder-grade" component. If you're upgrading or building for yourself, you'll likely pay a few extra bucks for an 850 Evo or similar unit.

    With that being said, any of the modern SSDs are better than a mechanical drive. Blech.
  • leexgx - Wednesday, April 27, 2016 - link

    this drive will likely be perfect for the older apple laptops that have that dodgy cable that does not support SATA 3 but the controller does (the cable fails if a high speed cable is used) i had to use a DVD HDD caddy on number of apple laptops due to that issue where it will not detect the SSD or HDD
  • leexgx - Wednesday, April 27, 2016 - link

    high speed drive is used (not cable is used) edit be nice on here but that's unlikely
  • Death666Angel - Friday, April 22, 2016 - link

    I'm guessing the marketing value for "Performance Samsung SSD inside" is considerably higher than comparable Sandisk or Crucial SSDs. And the 10 bucks off compared to the 850 means the margins remain. And if current 1TB laptop drives get replaced by these 250GB 750s, I think everyone is a winner. :D
  • Samus - Monday, April 25, 2016 - link

    It's funny you mention that because I would prefer a Sandisk or Crucial/Micron drive over a Samsung anyday.

    Have you ever tried warranting a Samsung drive? They are hell to deal with. And yes, I still have a sour metallic taste after the 840 Evo debacle that essentially was never fixed.

    I also think Crucial/Sandisks Marvell drives, albeit slower, are more consistent, stable and deal with power loss substantially better than the MGX. The fact Samsung is making an SSD with 35TBW endurance in 2016 is pretty damning. I've seen 20GB racked up on old Intel X25-M's in a matter of years so 35GB in a 5 year period isn't out of the question. Just about any other SSD or hard disk for that matter will handle double that no problem at the rated capacity.
  • vladx - Monday, April 25, 2016 - link

    " after the 840 Evo debacle that essentially was never fixed."

    Don't know what you mean, I also have a 840 EVO and can confirm the performances issues are gone after the 2nd fix.

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