Samsung PM841 512GB mSATA SSD Review – Performance and Capacity in a Client SSD

Samsung PM841 512GB mSATA SSD Featured ImageOn the TSSDR Test Bench today is the Samsung PM 841 mSATA SATA 3 SSD, this particular sample being the highest capacity mSATA SSD that we have tested to date at 512 GB.

Unlike the Mushkin Atlas 480GB mSATA SSD that we have reviewed previously, the PM841 is the first to be offered in a single PCB design and housing only four modules of memory, each being 128GB in size.

MythlogicOur sample Samsung PM841 512GB mSATA SSD was accompanied by an introduction to MYTHLOGIC Computers of Ann Arbor, Michigan, a high end gaming PC Company that easily stands above the crowd in SSD selection within configurations of their custom systems.

MYTHLOGIC’s goal is to provide the most custom options, achieving the highest level of performance, using the highest of quality parts, at a competitive price. Our thanks goes out to Josh Tacey, Director of Technical Operations at MYTHLOGIC, for offering us a sample of their first received PM841 shipment even before Samsung’s own offering of a sample for review.


The Samsung PM841 is an OEM client level SSD that is manufactured in capacities of 128, 256 and 512GB. This means that, other than through limited Amazon availabilityblank, it is not made available by Samsung for retail consumer purchase and might typically be found within pre-configured PC portable systems. At the time of this report, the PM841 was available in capacities of 128, 256 and 512GB, the highest capacity being only $449 which is an excellent price. Performance is listed at 540MB/s read and 330MB/s write with up to 95,000 IOPS and the PM841 has on board AES 256-bit encryption with a power draw of .005W idle and 3.44W active. PM841 warranty would be as listed through the company selling the system in which the SSD was contained.

Samsung PM841 512GB mSATA SSD Front


The Samsung PM841 MSATA SSD is under 10 grams in weight, constructed of a single printed circuit board (PCB), and it’s controller matches that of the Samsung 840 Pro family that we reviewed earlier. It contains Samsung’s own 3-core eight channel MDX controller (300MHz), along with four modules of their own 21nm TLC toggle mode NAND ,flash memory, each with a capacity of 128GB.

Samsung PM841 512GB mSATA PCB front

Also found just above the controller is Samsung’s 512MB DRAM cache memory which makes the only 100% company manufactured new generation SSD available today. This is the first we have ever seen 128GB capacity in a single memory module for a total of 512GB with four modules on board. Formatting the drive leaves the end user with 477GB of available storage.

Samsung PM841 512GB mSATA PCB Back

Considering the possibilities, Samsung could easily create a 2TB 6Gbps 840 Pro SSD by including 16 of these memory packages on a single 2.5″ notebook SSD PCB. For our testing, we have also used an Intel mSATA to SATA 3 adapter as seen here:

Samsung PM841 512GB mSATA SSD Adapter 1


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    Arthur Brownlee IV

    Thanks for the review, was looking to find a good high capacity SSD for my Ultrabook. Looks like I can swoop up the Samsung instead of the Atlas which I was hesitant about.

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    I’m wondering if this 512GB will be used in the new Samsung Series 900X3E (1080p screen). In USA, NP900X3E-A02US=128GB, NP900X3E-A03US=256GB and there is no trace of 512GB. While in UK, NP900X3E-A01UK=256GB, NP900X3E-A03UK=512GB and there is no trace of 128GB. Totally confusing.

    As of end of April, only NP900X3E-A02US is available at Amazon. I think that I will buy NP900X3E-A02US, then buy and replace by a 480GB Muskin. I hope that the Series 900X3E uses a mSSD and Muskin can fit into it.

    Samsung (like Apple) really overprices the storage as $(NP900X3E-A03US) – $(NP900X3E-A02US) ~ $500 >> expected $1 * 128GB = $128. If you compare, $(NP900X3E-A02US) + $(480GB Muskin) < $(NP900X3E-A03US) !!!!

    Any comment?

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      If you were hoping fot the reviewed drive, isn’t that cheaper than the Mushkin? They sold out within a day but should be restocked and available by end month so stay tuned. Nice systems though but I can’t see Samsung making a 512GB standard as it would cost too much for purchase. We should be happy that they are using their own mSATA SSDs finally…or are they?

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    Thanks for the review. I don’t see any other large capacity SSDs out there so I’ll be keeping an eye out for when they come back in stock. I presume these would be compatible with most systems? I have a Lenovo Ideapad Yoga 13…

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    Any chance to get firmware upgrades here? mine isn’t recognized by the Magician software from Samsung.
    (btw. the SSD came with my 900X4D)

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      Any chance to get firmware upgrades here? mine isn’t recognized by the Magician software from Samsung. Funny hitch though having bought it in a Samsung system and still not being able to use it with the Magician. Did Samsung Magician come pre-installed on the machine?

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        No it wasn’t unfortunately… I installed it myself to give it a try. I just read somewhere that the Magician supports consumer SSDs only and it seems like the PM841 isn’t one of those.

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    Ah and before I forget it, I only get 130mb/s write speed with the 128GB version. Read is around 500mb/s. Windows 8 x64, AHCI mode, Intel Rapid Technology deinstalled,…

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    Hi, I am currently ordering a MYTHLOGIC pollux 1613-Black. i got and Samsung pm841 256 gb as mSATA, and a Crucial m500 480 gb SSD. and acyually the crucial SSD is the same price as the pm841 512 gb, I read your great reviews on both of them, and i am wondering whether the pm841 512 gb could be better than the crucial as the main drive?
    And is the mSATA pm841 512 gb nearly as reliable or robust as the crucial m500 480 gb?


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    I’m not exactly sure where the drive is sold. Amazon, ebay, and the samsung website doesn’t seem to be offering the PM841 512GB mSATA drive. My guess it’s discontinued. Any info would be appreciated, thanks!

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    What about power consumption?

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    How would you obtain warranty services on a non retail product? I dont think Samsung would support the end user?

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    im confused… why is the mydigitalssd smart series scores better even tho this samsung one’s AS SSD benchmark score is better than smart series?

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    Les, Thanks for the review. I was not able to find any information about the SM841 from other sources. Is this a duplicate of the 840 or 840 Pro?

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      The 840 and 840 Pro are notebook drives whereas this is a mSATA. It is not retail and has been next to impossible to get from Day 1. Amazon has them on and off andf there are like 11 in stock right now. Click on our amazon link at the top of this page (SHOP AMAZON) and search Samsung PM841.

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    this is now the same ssd used by Dell XPS15 NEWEST Model.. It seems to be super fast.. I have the 512 gig with the i7-4702

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      Hi Mike,
      I’m thinking of getting the dell xps with 512ssd. Heard it’s it’s got modest speeds for an ssd but crucial m550 is much better.
      What do you think as I can either get your model or get the one below and swop the 1st drive.

      Any comments are much appreciated.


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        It depends on what you will be using it for Richard. If you haven’t got any plans to puch those SSDs, you will never notice any difference whatsoever. With respect to my choice of the PM841 and M550, there are arguments both ways but the M550 does have power failure protection.

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        Hi Les,

        Thank you for your very prompt reply. Looking at various reviews etc then it seems it’s best to stick with the Samsung ssd and enjoy it.
        Was looking at the crucial ssd as I’ve bought lots of stuff off them and always had a great product.
        In terms of performance, as it’s very little different I’ll stick with the std spec on the xps ssd 512.

        Many thanks again for your help as I stumbled onto this site and it looks very informative.
        Will keep using it.


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    Hi, My laptop is currently using a PM830…. Can PM841 substitute the PM830?, Are both compatibles?

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