Plextor S1G 256GB M.2 SSD Review 27

The use of MLC NAND flash on SSD are slowly being phased out by the use of TLC NAND flash to keep to cost low. But little did you know, while most SSD manufacturers no longer offers SSD with MLC NAND flash, Plextor has announced its last MLC NAND flash SSD, the S1 series lineup exclusively for the SEA region users back in October 2016.
The S1 series SSD consists of the S1C 2.5-inch SATA III SSD and S1G M.2 SSD, and special thanks to Plextor, we’ve managed to get our hands on the S1G 256GB M.2 SSD for today’s review. 
Sequential Read Speed**
Up to 510 MB/s
Sequential Write Speed**
Up to 310 MB/s
Random Read Speed***
Up to 74,000
Random Write Speed***
Up to 64,000
SMI SM2246
NAND Flash
DRAM Cache
128MB DDR3
Form Factor
M.2 2280
M.2 SATA 6.0 Gb/s
Power Connector
M.2 connector for DC 3.3V input
Data Connector
M.2 connector
Dimension (L x W x H)
80 x 22 x 2.3 mm / 3.15 x 0.87 x 0.09 inch
10g / 0.35oz (Max.)
Environment and Reliability
DC Requirement
3.3V / 2.0A (Max.)
0°C ~ 70°C / 32°F ~ 158°F (Operating)
1500G (Max.), at 1 msec half-sine
7 ~ 800Hz, 3.08Grms (Operating)
> 1,500,000 hours
Operating System Supported
Microsoft Windows OS / Linux OS
Agency Approval
Command Set Support
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Although it comes in the same 2280 form factor like most of the M.2 SSD we’ve got our hands on in the past, the Plextor S1G has a small, underutilized section on its PCB with no visible circuit nor components on it.  While it’s not exactly something that would affect the overall performance of the SSD itself, we find this rather disturbing as Plextor could have make it a 2260 form factor M.2 SSD instead of 2280.
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The Plextor S1G is equipped with Toshiba’s A19nm toggle NAND flash, Silicon Motion’s SM2246EN  controller that is capable of speeds over 540MB/s read and 410MB/s write with over 80,000K IOPS and a Nanya NT5CC128M16FP-DI DDR3-1600 memory chip with 128MB capacity that is responsible for the data buffering and compression operations on the drive.
Synthetic Benchmarks

AS SSD Benchmark
Widely used SSD benchmarking utility that uses incompressible data to simulate the worst possible scenario for an SSD and thus giving a much lower sequential read and write speed result than what has been stated by the manufacturer as result of the heavy workload.
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ATTO Disk Benchmark
The most frequently used benchmarking utility by many manufacturers for performance specification. As ATTO Disk Benchmark uses compressible data rather than compressible data, it results in higher benchmark scores. We’ve run the benchmark with transfer size ranged from 0.5KB to 8192KB and a total length of the test to be 256MB.
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Developed by a Japanese coder that goes by the nickname Hiyohiyo, CrystalDiskMark is one of the most frequent used SSD Benchmark utility to measure SSD’s read and write performance. 

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Anvil’s  Storage Utilities
By far the most complete SSD Benchmark utility available. The Anvil’s Storage Utilities not only comes with the standard SSD Benchmark function, it also includes other functions such as endurance testing and threaded I/O read, write and mixed tests and option to configure the compressibility of the test data.

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Real World Performance
We’ve run several tests using several SSD with at least 40% capacity occupied with various commonly played games to simulate some of the real world scenarios. 

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As it is not designed to run as fast the high-end M8Pe (2000 MB/s read and 900 MB/s write), 510 MB/s read and 470 MB/s write is pretty much the best you can expected from the Plextor S1G. It’s not the best when it comes to the performance numbers, but the Plextor S1G still managed to perform fairly well against the SATA III SSD we have in our list. 

Honestly, the performance numbers is never appealing if you’re the kind of users who afters M.2 SSD with high read and write speed. Of course, this doesn’t means that the Plextor S1G is a bad SSD that doesn’t worth spending your money on, as 510 MB/s read and 470 MB/s write is actually good enough for most users. What makes the Plextor S1G unique in it’s own way, is none other than the Toshiba MLC NAND flash, which offers higher life expectancy over most SSD that uses TLC NAND flash. 

The Plextor S1G 256GB M.2 SSD is expected to retail at around $150, a price which we find still reasonable, given that most SSD nowadays uses TLC NAND flash to keep to cost down.  

  • Decent read/ write performance
  • Equipped with MLC NAND that has higher life expectancy over TLC NAND 
  • Backed by 3-year limited warranty from Plextor


  • Underutilized section on the PCB
  • Exclusively only for SEA region
  • Only available in 128GB and 256GB

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