Mixed Random Read/Write Performance

The mixed random I/O benchmark starts with a pure read test and gradually increases the proportion of writes, finishing with pure writes. The queue depth is 3 for the entire test and each subtest lasts for 3 minutes, for a total test duration of 18 minutes. As with the pure random write test, this test is restricted to a 16GB span of the drive, which is empty save for the 16GB test file.

Iometer - Mixed 4KB Random Read/Write

The Samsung 950 Pro never had a clear lead on the mixed random I/O test, and then the OCZ RD400 raised the bar. The 960 Pro is 22% faster than that and is alone at the top.

Iometer - Mixed 4KB Random Read/Write (Power)

The 960 Pro has power draw comparable to the SATA SSDs that are less than half the speed, and clearly lower than the power draw of the other NVMe SSDs.

Most of these drives spend at least the first half of the test below 200MB/s and bring their score up with a strong finish of fast random writes. The 960 Pro hits 200MB/s in the second phase and continues increasing throughout the test, then finishes with a random write speed that beats even the Intel SSD 750.

Mixed Sequential Read/Write Performance

The mixed sequential access test covers the entire span of the drive and uses a queue depth of one. It starts with a pure read test and gradually increases the proportion of writes, finishing with pure writes. Each subtest lasts for 3 minutes, for a total test duration of 18 minutes. The drive is filled before the test starts.

Iometer - Mixed 128KB Sequential Read/Write

The 960 Pro's mixed sequential speeds are a big jump over any previous drive, with about a 30% advantage over the OCZ RD400A and over three times the performance of any SATA drive.

Iometer - Mixed 128KB Sequential Read/Write (Power)

The 960 Pro's power consumption is about the same as the OCZ RD400 and slightly higher than the 950 Pro, so it is only about 15% more efficient than any other drive.

At the beginning and end of the test the 960 Pro appears to be thermally limited with power consumption above 4W. In the middle of the test where it is typical to see the lowest performance, the 960 Pro doesn't even come close to dropping down to SATA speeds. Its nearest competitor in performance (the OCZ RD400) has much worse performance during the early read-heavy parts of the test.

Sequential Performance ATTO, AS-SSD & Idle Power Consumption
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  • JoeyJoJo123 - Tuesday, October 18, 2016 - link

    Not too surprised that Samsung, once again, achieves another performance crown for another halo SSD product.
  • Eden-K121D - Tuesday, October 18, 2016 - link

    Bring on the competition
  • ibudic1 - Tuesday, October 18, 2016 - link

    Intel 750 is better. The only thing that you can tell is random write 4K QD1-4. Also it's really bad when you don't have the consistency when you need it. There's nothing worse than a hanging application, it's about consistancy not outright speed. Which reminds me...

    When evaluating graphics cards a MINIMUM frame rate is WAY more important than average or maximum.

    Just like in racing the slowest speed in the corner is what separates great cars from average.

    Hopefully Anandtech can recognize this in future reviews
  • Flying Aardvark - Wednesday, October 19, 2016 - link

    Exactly. Intel 750 is still the king for someone who seriously needs storage performance. 4K randoms and zero throttling.
    I'd stick with the Evo or 600P, 3D TLC stuff unless I really needed the performance then I'd go all the way up to the real professional stuff with the 750. I need a 1TB M.2 NVME SSD myself and eager to see street prices on the 960 EVO 1TB and Intel 600P 1TB.
  • iwod - Wednesday, October 19, 2016 - link

    Exactly, when majority ( 90%+ ) of consumer usage is going to be based on QD1. Giving me QD32 numbers is like a Mpixel or Mhz race. I used to think we reached the limit of Random read write performance. Turns out we haven't actually improved Random Read Write QD1 much, hence it is likely still the bottleneck.

    And yes we need consistency in QD1 Random Speed test as well.
  • dsumanik - Wednesday, October 19, 2016 - link

    Nice to see there are still some folks out there who arent duped by marketing, random write and full capacity consistency are the only 2 things a look at. When moving large video files around sequential speeds can help, but difference between 500 and 1000 mb/s isnt much, you start the copy then go do something else. In many cases random write is the bottleneck for the times you are waiting on the computer to "do something", and dictates if the computer feels "snappy". Likewise, performance loss when a drive is getting full also makes you 'notice' things are slowing down.

    Samsung if you are reading this, go balls out random write performance on the next generation, tyvm.
  • Samus - Wednesday, October 19, 2016 - link

    You can't put an Intel 750 in a laptop though, and it also caps at 1.2TB. But your point is correct, it is a performance monster.
  • edward1987 - Friday, October 28, 2016 - link

    Intel SSD 750 SSDPEDMW400G4X1 PCI-Express-v3-x4 - HHHL
    AND Samsung SSD 960 PRO MZ-V6P512BW M.2 2280 NVMe
    IOPS 230-430K VS 330K
    ead speed (Max) 2200 VS 3500

    Much better in comparison http://www.span.com/compare/SSDPEDMW400G4X1-vs-MZ-...
  • shodanshok - Tuesday, October 18, 2016 - link

    Let me do a BIG WARNING against disabling write-buffer flushing. Any drive without special provisions for power loss (eg: supercapacitor), can really lose much data in the event of a unexpected power loss. In the worst scenario, entire filesystem loss can happen.

    What the two Windows settings do? In short:
    1) "enable write cache on the device" enables the controller's private DRAM writeback cache and it is *required* for good performance on SSD drives. The reason exactly the one cited on the article: for good performance, flash memory requires batched writes. For example, with DRAM cache disabled I recorded write speed of 5 MB/s on a otherwise fast Crucial M550 256 GB. With DRAM cache enabled, the very same disk almost saturated the SATA link (> 400 MB/s).
    However, a writeback cache imply some data loss risk. For that reason the IDE/SATA standard has some special commands to force a full cache flush when the OS need to be sure about data persistence. This bring us that second option...

    2) "turn off write-cache buffer flushing on the device": this option should be absolutely NOT enabled on consumer, non-power-protected disks. With this option enabled, Windows will *not* force a full cache flush even on critical tasks (eg: update of NTFS metadata). This can have catastrophic consequence if power is loss at the wrong moment. I am not speaking about "simple", limited data loss, but entire filesystem corruption. The key reason for such a catastrophic behavior is that cache-flush command are not only used for store critical data, but for properly order their writeout also. In other words, with cache flushing disabled, key filesystem metadata can be written out of order. If power is lost during a incomplete, badly-reordered metadata writes, all sort of problems can happen.
    This option exists for one, and only one, case: when your system has a power-loss-protected array/drives, you trust your battery/capacitor AND your RAID card/drive behave poorly when flushing is enabled. However, basically all modern RAID controllers automatically ignores cache flushes when the battery/capacitor are healthy, negating the needing to disable cache flushes software-side.

    In short, if such a device (960 Pro) really need disabled cache flushing to shine, this is a serious product/firmware flaw which need to be corrected as soon as possible.
  • Br3ach - Tuesday, October 18, 2016 - link

    Is power loss a problem for M.2 drives though? E.g. my PSU's (Corsair AX1200i) capacitors keeps the MB alive for probably 1 minute following power loss - plenty of time for the drive to flush any caches, no?

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