SanDisk A110 PCIe SSD: Armed With The New M.2 Edge Connector

Results: Tom's Hardware Storage Bench v1.0, Continued

Service Times

Beyond the average data rate reported on the previous page, there's even more information we can collect from Tom's Hardware's Storage Bench. For instance, mean (average) service times show what responsiveness is like on an average I/O during the trace.

It would be difficult to graph the 10+ million I/Os that make up our test, so looking at the average time to service an I/O makes more sense. For a more nuanced idea of what's transpiring during the trace, we plot mean service times for reads against writes. That way, drives with better latency show up closer to the origin; lower numbers are better.

Write latency is simply the total time it takes an input or output operation to be issued by the host operating system, travel to the storage subsystem, commit to the storage device, and have the drive acknowledge the operation. Read latency is similar. The operating system asks the storage device for data stored in a certain location, the SSD reads that information, and then it's sent to the host. Modern computers are fast and SSDs are zippy, but there's still a significant amount of latency involved in a storage transaction.

The A110 achieves phenomenally low write service times in this chaotic plot. Naturally, the explanation is fairly simple. Most of the read service time accumulated during the trace is a mix of random and sequential transfers, both small and large. Write requests predominantly include 4 KB random accesses and large-block size sequentials. Given a substantial advantage in sequential writes, the A110 services requests fast enough to put some distance between itself and the other 256 GB-class SATA SSDs.

It'd be wrong to characterize read service times as mostly the same for the drives we tested, but it's not fair to call them radically different, either. With that in mind, the A110 bests SanDisk's own Extreme II, though it doesn't quite land in the upper echelon.

Then again, with write performance like this, who cares? Write service times are far more varied anyway, demonstrating a range between a little more than 400 and more than 2500 microseconds. 

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19 comments
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  • Mike Friesen
    Awesome new stuff. Can't wait to see if this drive actually uses the full potential of the M2, and if Samsung or OCZ can one-up them.
    0
  • cryan
    Anonymous said:
    Awesome new stuff. Can't wait to see if this drive actually uses the full potential of the M2, and if Samsung or OCZ can one-up them.


    Samsung actually has some pretty awesome M.2 PCIe action going on. We're trying to get our hands on everything, so stay tuned.


    Regards,
    Christopher Ryan
    5
  • Anonymous
    It will be nice to see vendors implement the NVMe connectors in the desktop mobo's, which in turn will redefine case design, as less storage space will be required for storage. I am aware that the initial intent is to direct these at the mobile market, but desktops can benefit as well.
    0
  • cryan
    Anonymous said:
    It will be nice to see vendors implement the NVMe connectors in the desktop mobo's, which in turn will redefine case design, as less storage space will be required for storage. I am aware that the initial intent is to direct these at the mobile market, but desktops can benefit as well.


    You'll really see NVMe take off on the desktop with the move towards SATA Express. A SSD on SATA Express will leverage NVMe and two PCIe Gen 3 lanes. Though some motherboards will (and already do) have M.2 connectors, M.2 really makes more sense in mobile applications. M.2 will only get traction on the desktop insofar as it will begin to replace mSATA. Tons of mainboards, especially smaller form factor products embrace mSATA, and moving to M.2 is a natural transition. However, M.2 drives are hard to find right now, and we really won't see a plethora of options until next year.

    Regards,
    Christopher Ryan
    2
  • nekromobo
    I got M.2 toshiba ssd in my Sony Vaio Pro 13.. review that?

    and it should have samsung M.2 in some countries..
    1
  • CaedenV
    I may no longer have motivation to upgrade my system based on CPU specs, but with DDR4, M.2, new restive storage based SSDs, and better chipset features I will still have enough reason to upgrade in a year or two.
    2
  • jimmysmitty
    Anonymous said:
    Anonymous said:
    It will be nice to see vendors implement the NVMe connectors in the desktop mobo's, which in turn will redefine case design, as less storage space will be required for storage. I am aware that the initial intent is to direct these at the mobile market, but desktops can benefit as well.


    You'll really see NVMe take off on the desktop with the move towards SATA Express. A SSD on SATA Express will leverage NVMe and two PCIe Gen 3 lanes. Though some motherboards will (and already do) have M.2 connectors, M.2 really makes more sense in mobile applications. M.2 will only get traction on the desktop insofar as it will begin to replace mSATA. Tons of mainboards, especially smaller form factor products embrace mSATA, and moving to M.2 is a natural transition. However, M.2 drives are hard to find right now, and we really won't see a plethora of options until next year.

    Regards,
    Christopher Ryan


    That's what I was thinking. SATA Express is going to be fast enough for now as I have used PCIe SSDs before (OCZ Revo based drive) and compared to my 520 its hard to notice a difference, especially since there are other bottlenecks stopping it from being able to utilize that bandwidth.

    This will be great for ultra portable systems though and ITX systems.
    0
  • cryan
    Anonymous said:
    I got M.2 toshiba ssd in my Sony Vaio Pro 13.. review that?

    and it should have samsung M.2 in some countries..


    Absolutely... just send it my way and consider it done.

    Regards,
    Christopher Ryan
    2
  • m32
    Christopher Ryan, I'll take this off of your hands.

    Regards,
    m32
    0
  • mikeangs2004
    will there be RAID or SLI/CFX for PCIe based SSD's?
    I don't think so b/c it's already way above 6G limit.
    0
  • markhahn
    the power numbers don't make a lot of sense. I suspect either the pcie interface is being kept in a high-power mode (plls running, etc) or else your molex is supplying power to other stuff on the board. (there must be a dc-dc regulator on the auxiliary card, since molex provides only 12,5.)
    0
  • cryan
    Anonymous said:
    the power numbers don't make a lot of sense. I suspect either the pcie interface is being kept in a high-power mode (plls running, etc) or else your molex is supplying power to other stuff on the board. (there must be a dc-dc regulator on the auxiliary card, since molex provides only 12,5.)


    This is almost certainly true. I mean, we know it uses DC to DC to step the 5v down to 3.3v. But oddly, SanDisk rates the max write power consumption at 5.5w, and I could only get it max at 3.5w. Of course, it also possesses a deep slumber state, but that's contingent on having a L1.0 PCIe endpoint, and that hasn't even been ratified yet by PCI-SIG.

    So definitely take the power consumption results with a grain of salt. There are challenges to testing this drive in this way.


    Regards,
    Christopher Ryan
    0
  • cryan
    Anonymous said:
    will there be RAID or SLI/CFX for PCIe based SSD's?
    I don't think so b/c it's already way above 6G limit.


    If you happened to have the ability to run two+ PCIe SSDs, M.2 or otherwise, you can always soft-raid them. There are reasons why you'd want to avoid such a setup, but it'd totally work. Intel's 910 PCIe SSD shows 2 or 4 drives to the OS and then they can be soft-raided from there, for instance.


    Regards,
    Christopher Ryan
    0
  • abbadon_34
    what command line switches were use in robocopy?
    0
  • mikeangs2004
    Is there TRIM/garbage collection?
    0
  • Dax corrin
    Awesome stuff, wish I could afford it.
    0
  • Blaise170
    It seems like new progress is being made in the field of NAND every day. I can't wait until you can get high capacity drives for around the same price as HDDs, but I've heard that even as late as 2017 SSD storage will only have a 33% share.
    0
  • ryyple
    I'm a complete novice to all this stuff, yet I have a few questions that maybe someone can answer.

    Are these M2 devices still considered SATA drives?
    Using a PCIe (or other) interface for the M2 how could you clone these devices?
    Can these devices then be cloned using a standard HDD duplicator?
    Is there such a thing as a M2 "adapter" that plugs into the above duplicator?

    Thanks for your response.
    0
  • tpidner17
    Christopher,

    On page four of this review, in the maximum 4kb speed chart, it says "in MB/s [higher is better]." However, shouldn't that refer to the fact that it is measuring max IOps, rather than write speed? It seems like a type to me, so I wanted to let you know.
    0