Toshiba HG5D Series SATA M.2 SSD Review (512GB) – Amazing Performance in a SATA M.2 SSD


By now, many are aware that there is a new SSD standard known as NGFF or M.2.  NGFF is actually a slang term that started the process rolling and means ‘next generation form factor’.  If you have been following our reviews as of late, you would have also learned that, within the M.2 standard, there are two separate SSD configurations.  On one hand we have SATA M.2 SSDs capable of 6Gbps speeds above 550MB/s while, on the other, native PCIe M.2 SSDs can reach as high as 2GB/s through the use of four PCIe 2.0 lanes.  The easy way to differentiate between the two is by the interface, SATA having two notches whereas native PCIe  has one.

M.2 Comparison

Up to this point, we have reviewed one of each with the ADATA AXNS360E 128GB SATA M.2 SSD reaching speeds of 550MB/s while the Samsung XP941 512GB PCIe M.2 SSD more than doubled that at 1.2GB/s.   The important thing for all to remember is that, regardless of the speed, the typical user will never be able to visibly observe any difference whatsoever between either SSD.  The typical users lightning fast SSD experience is the result of disk access times which are the same between most SSDs, whereas the new native PCIe transfer speeds will be a godsend to media professionals who transfer hundreds of gigabytes of highly incompressible media daily.


Known as the HG5d Series of Toshiba solid state drives, the cSSD (or client SSD) can be found in PC systems worldwide, however, is not available through retail sales.  The HG5d cSSD family is comprised of 2.5″ notebook, mSATA and M.2 form factor SSDs with capacities of 60, 128, 256 and 512GB.  All speak to low power consumption, three-year warranties applicable only to manufacturing partners, and all take advantage of Toshiba’s newest 19nm Toggle Mode 2.0 MLC memory.

Toshiba HG5d cSSD

 The M.2 family of the HG5d cSSD is a SATA M.2 SSD and listed performance is variable, depending on capacity.  Our sample 512GB M.2 SSD can reach 534MB/s read and 482MB/s write with 90KIOPS read and 35KIOPS write.  128 and 256GB capacities have the same read performance but write speeds are listed at 471MB/s with read IOPS a bit lower at 80K.

Toshiba THNSH 512GB SSD PCB Front

 The Toshiba HG5d Series SATA M.2 cSSD contains the Toshiba TC58NC5HA9GST eight channel controller and eight modules of Toshiba Toggle Mode 2.0 NAND flash memory, each module being 64GB in capacity.  Although the hardware of this controller is manufactured by Marvell, Toshiba engineering and firmware expertise plays a large part in its success and this is one of the first times we have seen a Marvell controller that did not use some type of DRAM cache.

Toshiba THNSH 512GB SSD PCB Back

Although the total RAW capacity if this M.2 SSD is 512GB (64×8), the total available space for the user after formatting is 477GB.

Toshiba Memory


Crystal Disk Info provides some excellent information about the SSD itself to include its health, product information, ‘power on’ information as well as the characteristics of the SSD. We can see that the SSD is capable of TRIM as it is not grayed out as with AAM.

Toshiba 512GB M.2 Crystal DiskInfo


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    hmm… too slow. Really M.2(NGFF)’s release?
    It’s likes only swapping SATA6G and PCIe I/O.

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    I have to wonder about a few things:

    1. Why is SATA3 still used when SATAexpress (12Gbps) is already here? SATA3 has been around for several years and it’s already showing its age…it’s the reason that SSDs are bottle-necked at around 550MB/s.

    2. Even when SATA3 makes way for SATAexpress, it will be already outdated, as 12Gbps (1.5GB/s) can already be surpassed by high-end SSD, which can reach over 2.5GB/s.

    3. The claim that SATA3 SSD are already fast enough for most consumers is just bullshit.

    In computers, the name of the game is SPEED. Anyone trying to stop/uphold the evolution is only doing consumers a dis-service.

    4. Besides SATA and PCIe, there’s also SAS, which currently tops at 12Gbps (same as SATAexpress). SAS is usually reserved for workstations and servers. Why hasn’t SAS trickled down to consumer PCs? Why have a different standard, if SAS has some advantages over SATA? Is it merely to charge extra for a more “professional” port?

    5. What about that NAND flash that can sit in a RAM slot and have the best & fastest connection with the least latency? It’s faster than SATA3, SATAespress, SAS12 and even faster than PCIe x8.
    For example, Diablo MCS:

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      What the hell are you talking about? SATA Express is hardly “here”. I’d love for you to show me some laptops that contain SATA Express drives. Yea, didn’t think so.

      And SAS? Really? If SAS was going to make it into mainstream computers, it would have happened AGES ago.

      As for your shot at this article (and site), you will be hard pressed to find another site dedicated to SSDs with as much history as this forum/blog. PCIe is where it’s at, bro-sees.

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        SATA express (SATA 3.2) is coming, and I believe will be in consumer machines before the end of this year. My guess is that the only reason for its existence is support for DEV-SLP, which PCIe devices do not support. DEV-SLP is important for laptops where battery life is crucial.

        I love this site, and fully support it. It brings very interesting information, which is not usually found anywhere else.

        My wish was simply that manufacturers switch to PCIe 3.0 x4 (or even x8) to enable the full potential of SSDs. The SATA standard is simply getting in the way.
        Manufacturers will need to find a solution to bring PCIe power consumption down.

        It could be that SATA express storage will be used mainly on battery-powered devices, and PCIe 3.0 storage will be used mainly on desktops where more performance is more important than saving power.

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        1. SSD are already too fast for current Operating Systems, which still have many depdendencies on timing hard-coded somewhere. Bottleneck is 1. OS 2. Drivers 3. Applications 4. “Protein Interface” i.e. human
        2. SSD are already sacrificing most important characteristic – RELIABILITY and DURABILITY chasing still unnecessary performance.

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        “… chasing still unnecessary performance.”

        Awwww. Eric, that’s so cute. Did you just get your first leapfrog computer? Well, at least you haven’t upgraded to SSD yet. That goes right up there with: “640k memory should be enough for anyone.” Only you actually said it — after it was outdated! I hope you realize that the most constrictive bottleneck in data transfer rates has been the hard drive for a looooong time. That’s why starting a program used to take 20 seconds instead of 2 and why booting used to take 60 seconds instead of 6. Now run along and go upgrade your computer with a new SSD drive. You will swear you bought a new computer… from the future!

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        My bad… Antey, Not Eric. Very sorry for the mixup, Eric.

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    The last slide is interesting for me in particular, because check out that Plextor M5M beating out everything but the XP941 (no surprise there). When I sold my maxed-out Mac mini, so I could afford my new BTO iMac with PCIe SSD, I was forced to use another mini in the meantime while waiting for its arrival, but I had sold my 250GB 2.5″ Samsung 840 EVO SSD along with it.

    Luckily, I had already ordered and received an mSATA-to-2.5″ SATA converter, so I took out my 128GB Plextor M5M that I had purchased for caching purposes in my Drobo 5D, and put it in the Mac mini. I was BLOWN AWAY! It has a Marvell controller, so the performance difference between the 128GB and 256GB capacities is quite negligible, but this tiny little mSATA SSD beats out the Samsung 840 EVO, the Intel 520 Series, the OWC Extreme and every SSD that I’ve owned prior. I can’t wait to see how much faster the XP941 in the new iMac is as compared to the amazing performance of the Plextor M5M series. I just wanted to mention it, because I really didn’t expect that!

    P.S.: Plextor is coming out with its next-gen. M6 series shortly, so I would only buy an M5 series variant, if you can find a crazy awesome deal for it. 😉

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    Where can you buy this? RamCity doesn’t have it :/

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      Hi Mike,

      Unfortunately I am not aware of anywhere for retail sales. RAMCity would have been my best guess as well. It is a M.2 client (non-retail) SSD.

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        This is pretty much the best SSD for a Samsung Ativ Book 9 940X3G eh?

        It is a SATA M.2 looking @:

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        Yup…it seems to be a SATA M.2. Availability is the next issue. At retail, I have ONLY seen Intel M.2 SSDs listed on Amazon and Newegg in very small amounts. I might ask RAMCity if they can get you ANY SATA M.2. What exactly are you looking for, simply a larger capacity?

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        512GB and the fastest possible .. whatever options then can provide would be great… I’m sure all SATA M.2 owners would be interested

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        This is actually a bit amusing because, when mSATA first came out, i was the first to tell manufacturers to get it out to the retaiul market. Most declined and stated that there was no need for M.2 just yet, failing to think about the millions of Lenovo notebooks that contained them. The result was a vry large shortage of demand where, just like now, you have to keep your eyes open for wherever they pop up fast. I have been watching the 80 and 300GB Intel M.2 530 on Amazon and newegg for a few days and they are gone fast!

        I will keep an ear open Mike!

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        When my AB9+ arrives soon its 256GB… so I would need a 512GB to make it worth while… now doing a clone from one to the other is going to be interesting, how to do it

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