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 availability, 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