Plextor PX-M5S 256GB Solid State Drive Review

Plextor skips M4 and jumps straight to the M5 Series. The first product in this new series brings IMFT flash in and with it we should see a lower price.

Manufacturer: Plextor
16 minutes & 19 seconds read time


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For Plextor, just making a fast and cost effective solid state drive is a starting point. The company's products are some of the most reliable on the market today, a feature Plextor uses in their marketing. The claim is an average annual failure rate (AFR) of just .59%. While this number isn't easily verified, Plextor claims their .59% is the lowest in the industry. We've written about solid state drives since early 2008 and over that course of time two issues have risen to the surface in our feedback. The first is reliability, users want to know their SSD is going to be reliable and not flake out while holding user data.

The second issue we hear about is the price. I don't think anyone will ever not list price as an issue when facing a buying decision. It is just human nature, even if SSDs were at the same dollar per GB as HDDs, people will still want the price to go down. To date, Plextor SSDs cost more than similar capacity Team LSI SandForce products. The Plextor drives have always used premium Toshiba flash, exclusive firmware/programming from LiteON and surface mount components built by Japanese firms who pride themselves on obsessive tolerances. With that in mind and the claimed industry leading AFR, we can conclude that Plextor SSDs don't cost more just for the hell of it.

The new Plextor PX-M5S appears to be Plextor's answer for producing a product that will cost less than the previous M3 Series of drives. Plextor turned to Micron to supply the NAND flash for the M5S, more specifically 25nm synchronous flash that we hear costs much less than 24nm Toshiba Toggle Mode flash that was found on the M3S and M3 Pro.

At the time of writing the Plextor M5S was not available at Newegg or any other e-tailer that we normally shop at. Plextor did send over their MSRP pricing, but we were warned these prices will not last for long.

So how does the Plextor PX-M5S stack up in price and performance to the M3S/M3 Pro models, you'll have to keep reading to find out.

Specifications, Pricing and Availability

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The Plextor PX-M5S comes in three capacity flavors and all three have a different performance envelope just like previous models based on the Marvell 88SS9174 controller. The capacity sizes offered are 64GB, 128GB and the model we have for testing today, 256GB.

All three capacity sizes list the same 520MB/s read speed, but the sequential write speed, as well as the IOPS performance differs by capacity. The 64GB model has a sequential write speed of 90MB/s, 128GB has 200MB/s and the 256GB has 390MB/s. Each capacity size also has an increasing volume of DRAM cache as you scale through the product line. The 64GB starts off with 128MB, 128GB has 256MB and the 256GB model gets an impressive 512MB of cache to increase write performance and handle data mapping.

Just a few months ago we concluded that the Plextor M3S and M3 Pro were in the running for the best 128GB SSD on the market today. Hopefully we'll be able to test the 128GB M5S when available in the middle of August, when production ramps up. With a brief look at the reported specs between the M3S and the M5S at the 128GB capacity size, we see the new M5S model gains 10MB/s in the sequential read category, but loses 10MB/s in the sequential write category. We'll just call that one a draw.

The larger 256GB capacity size shows the new M5S gaining 10MB/s of sequential performance in both the read and write category. The advantage in sequential performance goes to the M5S. IOPS performance is also increased for the new M5S over the M3S and brings it much closer to the performance of the M3 Pro 256GB.

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One of the reasons we like the Plextor line of SSDs products is the custom firmware. Plextor calls it True Speed, but we would call it a very aggressive background garbage collection (GC). When it comes to consumer SSDs, write amplification isn't too big of a deal because most of us aren't pounding the drive 24/7 and expecting it to last for 10 years like the enterprise sector. SSDs based on SandForce technology don't use background GC so their write amplification is tiny. They do get help from other proprietary tech as well, but nearly all of that technology was ported from their enterprise products. Plextor on the other hand embraces background GC and their drives are able to perform well even in environments with TRIM. If you are using RAID or an OS without TRIM then you want background GC to keep the drives performance at their best. Even in TRIM environments, having a good background garbage collection system will aid in retaining peak performance... but your drive will not last as long. Since this 25nm flash is rated for 3000 PE cycles we are talking about years of service, around 8 to 10 under average consumer workloads.

As we mentioned, the Plextor M5S offers performance higher than the M3 and very close to the M3 Pro model. Now it is time to talk about the price and availability. We were told the production ramps up in August so you can expect an August release to e-tailers. Plextor MSRP is set at $99.99 (64GB), $159.99 (128GB) and $299.99 (256GB). We are not sure if Plextor plans to reduce the price of the M3/M3 Pro products or if the M5 Series will drop in between the M3 and M3 Pro right from the start. Both of the M3 products have already dropped in price since their release so they have the advantage of the e-tail pricing structure already, launch at MSRP and then fight it out with competition products in a large scale SSD price war. We thing the lower cost IMFT flash will aid in making the Plextor M5 products act like a tank in the price war, getting out in front of the M3 products and going head to head with Team LSI SandForce. I think it will take a couple of weeks, but the M5 products should eventually cost less than the M3 products. I'm not a market analyst, but I play one on the internet. Plextor may have different plans for the M5S, but my best guess, at this time, leads me to believe this product is more about getting high quality Plextor SSDs down to competitive price points.

You may wonder why we'd make such a bold claim about the M5 Series price even when we have contradicting data from Plextor directly in the form of MSRP pricing. Here are two reasons; the M5S comes with a three year warranty, down two years from the M3 and M3 Pro. Our sample also shipped without a desktop adapter bracket. The adapter bracket may have been just an oversight since our sample was a pre-production model, but in years past, the early samples did ship with a desktop adapter bracket.


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When released in August this is what the retail package will look like for the M5S. There isn't a lot of data on the front of the package, but most of these will sell from e-tail shops and not retail environments.

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For those that do make it to store shelves, Plextor has loaded the back of the box with specifications galore so you can get your nerd on while standing at Fry's or other brick and mortar stores.

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The inner packaging kept the drive separate from, well nothing. Inside our sample we found a drive and a plastic container that keeps the drive from sliding around. I'm sure the drive will ship with some kind of paper documentation, but the M5S doesn't come anywhere close to the included accessories we found on the M2 or M3 class of products.

Plextor PX-M5S 256GB SSD

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The drive itself looks identical to the M2 model we reviewed quite some time ago.

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On the back we found the model and serial number as well as the capacity size.

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We've seen this case from Plextor on several occasions.

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The SATA power and data ports are located where they should be as well as all of the mounting locations. You will not have an issue running this drive in your notebook. Desktops will require an adaptor bracket in most cases and this drive is not qualified for use in notebooks/ultrabooks requiring 7mm Z-height.

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Inside we found the Marvell 88SS9174-BLD2 controller paired with dual Nanya DRAM with 256GB capacity each for a total of 512MB DRAM.

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Micron NAND flash ICs are new for Plextor and this capacity size uses sixteen total, eight on each side.

Benchmarks - Test System Setup and ATTO Baseline Performance

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We would like to thank the following companies for supplying and supporting us with our test system hardware and equipment: AVADirect, GIGABYTE, LSI, Corsair and Noctua.

You can read more about TweakTown's Storage Product Testing Workstation and the procedures followed to test products in this article.

In order to fully utilize SATA III you need a system with native SATA III support. P67, Z68, Z77 and X79 systems are preferred, but AMD has made advances in their newer SATA III systems as well. Older X58 systems with Marvell based SATA III ports do not deliver the same high levels of performance, so we recommend newer systems when available.

ATTO Baseline Performance

Version and / or Patch Used: 2.34

ATTO is used by many disk manufacturers to determine the read and write speeds that will be presented to customers.

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Just as Plextor is as obsessive with the components used in their products, their performance claims are equally conservative. In our testing with the 256GB M5S, we achieved a write speed of just over 400MB/s - a nice boost over the claimed 390MB/s. Read speed was recorded at nearly 540MB/s.

Benchmarks - HD Tune Pro

HD Tune Pro

Version and / or Patch Used: 4.00

Developer Homepage:

Product Homepage:

HD Tune is a Hard Disk utility which has the following functions:

Benchmark: measures the performance

Info: shows detailed information

Health: checks the health status by using SMART

Error Scan: scans the surface for errors

Temperature display

HD Tune Pro gives us accurate read, write and access time results and for the last couple of years has been gaining popularity amongst reviewers. It is now considered a must have application for storage device testing.

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We included the Plextor M3 in our charts for today and also reordered the archive results to place all of the Plextor drives at the top. In the sequential real test across the drives we found the new M5S a little slower on average when compared with the M3 class of drives with Toshiba flash.

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Benchmarks - AIDA64 Random Access Time

AIDA64 Random Access Time

Version and / or Patch Used: 1.60

Developer Homepage:

Product Homepage:

AIDA64 offers several different benchmarks for testing and optimizing your system or network. The Random Access test is one of very few if not only that will measure hard drives random access times in hundredths of milliseconds as oppose to tens of milliseconds.

Drives with only one or two tests displayed in the write test mean that they have failed the test and their Maximum and possibly their Average Scores were very high after the cache fills. This usually happens only with controllers manufactured by JMicron and Toshiba.

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The read access time for the new M5S stays around .05 milliseconds and mimics the results we achieved with the M3 Pro.

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The write latency is just a hair more than the preview generation products from Plextor, but still much quicker than the Crucial m4 and Team LSI SandForce products.

Benchmarks - CrystalDiskMark


Version and / or Patch Used: 3.0 Technical Preview

Developer Homepage:

Product Homepage:

Download here:

CrystalDiskMark is a disk benchmark software that allows us to benchmark 4K and 4K queue depths with accuracy.

Key Features:-

* Sequential reads/writes

* Random 4KB/512KB reads/writes

* Text copy

* Change dialog design

* internationalization (i18n)

Note: Crystal Disk Mark 3.0 Technical Preview was used for these tests since it offers the ability to measure native command queuing at 4 and 32.

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In CDM we're looking the 4K and native command queuing performance. We've long know that Toshiba Toggle Mode flash does really well in the 4K performance area and that is shown here as well. The M5S 256GB with Micron flash is around 5MB/s slower than the Toggle models. That deficit scales to the QD4 test, but the QD32 test is actually won by the new model by a small margin when just looking at the Plextor drives.

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When writing 4K data the M5S is around 25MB/s slower than the previous Plextor drives in the chart. Just as with the read test, the QD4 results show the M5S down again, but the QD32 shows the performance in between the M3 and M3 Pro.

In this test we also see the sequential write speed of all the drives using incompressible data. The new M5S is much faster with incompressible data when compared to the SandForce based drives.

Benchmarks - PCMark Vantage Hard Disk Tests

PCMark Vantage - Hard Disk Tests

Version and / or Patch Used: 1.0.0

Developer Homepage:

Product Homepage:

Buy It Here

PCMark Vantage is the first objective hardware performance benchmark for PCs running 32 and 64 bit versions of Microsoft Windows Vista. PCMark Vantage is perfectly suited for benchmarking any type of Microsoft Windows Vista PC from multimedia home entertainment systems and laptops to dedicated workstations and high-end gaming rigs. Regardless of whether the benchmarker is an artist or an IT Professional, PCMark Vantage shows the user where their system soars or falls flat and how to get the most performance possible out of their hardware. PCMark Vantage is easy enough for even the most casual enthusiast to use yet supports in-depth, professional industry grade testing.

FutureMark has developed a good set of hard disk tests for their PCMark Vantage Suite. Windows users can count on Vantage to show them how a drive will perform in normal day to day usage scenarios. For most users these are the tests that matter since many of the old hat ways to measure performance have become ineffective to measure true Windows performance.

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HDD1 - Windows Defender

HDD2 - Gaming

HDD3 - Windows Photo Gallery

HDD4 - Vista Startup

HDD5 - Windows Movie Maker

HDD6 - Windows Media Center

HDD7 - Windows Media Player

HDD8 - Application Loading

In the real-world test with all of the drives empty the Plextor M5S loses quite a bit of ground to the previous M3 class from Plextor.

Benchmarks - PCMark Vantage - Drives with Data Testing

For a complete breakdown on the Drives with Data Testing please read this article. You will be able to perform this test at home with the files provided in the article - full instructions are included.

- Brief Methodology

SSDs perform differently when used for a period of time and when data is already present on the drive. The purpose of the Drives with Data testing is to show how a drive performs in these 'dirty' states. SSDs also need time to recover, either with TRIM or onboard garbage collection methods.

Drives with Data Testing - 25%, 50%, 75% Full States and Dirty / Empty Test

Files needed for 60 (64GB), 120 (128GB), 240 (256GB)

60GB Fill " 15GB, 30GB, 45GB

120GB Fill - 30GB, 60GB, 90GB

240GB Fill " 60GB, 120GB, 160GB

Empty but Dirty - a test run just after the fill tests and shows if a drive needs time to recover or if performance is instantly restored.

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HDD1 - Windows Defender

HDD2 - Gaming

HDD3 - Windows Photo Gallery

HDD4 - Vista Startup

HDD5 - Windows Movie Maker

HDD6 - Windows Media Center

HDD7 - Windows Media Player

HDD8 - Application Loading

While testing all of the drives at various states of data present on the drives we found that the M5S is quite a bit slower than the M3 and M3 Pro. Using the 50% full as a market, we see that the M5S is down to just 36K Marks, or roughly half its fresh out of box (FOB) performance.

Benchmarks - AS SSD

AS SSD Benchmark

Version and / or Patch Used: 1.2.3577.40358

Developer Homepage: Alex Intelligent Software

Product Homepage: Alex Intelligent Software

Download here:

AS determines the performance of Solid State Drives (SSD). The tool contains four synthetic as well as three practice tests. The synthetic tests are to determine the sequential and random read and write performance of the SSD. These tests are carried out without the use of the operating system caches.

In all synthetic tests the test file size is 1GB. AS can also determine the access time of the SSD, the access of which the drive is determined to read through the entire capacity of the SSD (Full Stroke). The write access test is only to be met with a 1 GB big test file. At the end of the tests three values for the read and write as well as the overall performance will be issued. In addition to the calculated values which are shown in MB/s, they are also represented in IO per seconds (IOPS).

Note: AS SSD is a great benchmark for many tests, but since Crystal Disk Mark covers a broader range of 4K tests and HD Tune Pro covering sequential speeds, we will only use the Copy Benchmark from AS SSD.

- Copy Benchmark

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All three of the Plextor drives in the chart use the same Marvell controller with slightly different firmware and programming. In this test we see that Plextor spent quite a bit of time working on file transfer performance, an area where the new M5S is much faster than previous models.

Benchmarks - Anvil Storage Utilities

Anvil Storage Utilities

Version and / or Patch Used: BETA 11

So what is Anvil Storage Utilities? First of all, it's a storage benchmark for SSDs and HDDs where you can check and monitor your performance. The Standard Storage Benchmark performs a series of tests, you can run a full test or just the read or the write test or you can run a single test, i.e. 4K DQ16.

Anvil Storage Utilities is not officially available yet but we've been playing with the beta for several months now. The author, Anvil on several international forums has been updating the software steadily and is adding new features every couple of months.

The software can be used several different ways and to show different aspects for each drive. We've chosen to use this software to show the performance of a drive with two different data sets. The first is with compressible data and the second data set is incompressible data. Several users have requested this data in our SSD reviews.

Compressible Data

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Incompressible Data

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The Plextor M5S takes a small hit when working with incompressible data, but not the same sledge hammer smash that we find with LSI SandForce based drives.

Benchmarks - Passmark

Passmark Advanced Multi-User Tests

Version and / or Patch Used: 6.1

Developer Homepage:

Test Homepage:

Many users complain that I/O Meter is too complicated of a benchmark to replicate results so my quest to find an alternative was started. Passmark has added several multi-user tests that measure a hard drives ability to operate in a multi-user environment.

The tests use different settings to mimic basic multi-user operations as they would play out on your server. Variances is read / write percentage as well as random / sequential reads are common in certain applications, Web Servers read nearly 100% of the time while Database Servers write a small amount of data.

The Workstation test is the only single user environment and will be similar to how you use your system at home.

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Plextor has an interesting way of advertising their SSDs, calling them server class controllers. That doesn't mean your Plextor SSD is ready to take on the best from STEC or Pliant (now part of SanDisk), but under some circumstances we can see the M5S making an appearance in servers.

Final Thoughts

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Across the board we can say that the Plextor M5S is a little slower than the M3 Pro. There were a couple of places, mainly when transferring files, where the M5S was faster, but the M3 Pro appears to still be Plextor's flagship offering. Looking back at Plextor's track record with the M2, then M2 Pro, M3 followed by the M3 Pro, we're pretty sure Plextor will launch an M5 Pro model in the next 30 to 60 days. At that time the M3 Pro may take a back seat to the M5 Pro, but we'll have to wait and see.

On its own, the Plextor M5S 256GB delivers a lot of performance when each category is broken down into specific areas for measurement. Putting it all together with PC Mark's Vantage suite tells us a different story, though. In Vantage the M5S was quite a bit slower than the M3 and M3 Pro. A little more shocking was the performance with 50% of the user capacity filled with data. That was also an area where we saw the M5S losing to the M3 class by a large margin.

What we don't know yet is what Plextor tuned in the programming of this drive. The Marvel controller is based on an ARM platform and we've seen some companies tune for one area over another. The resource pie is only so large with these controllers and normally we get a good feel for what areas have increased or decreased. With this release we're kind of scratching our heads because it's like Plextor took a base M3 and just changed the flash to standard run of the mill Micron 25nm. With the new flash came slower performance and that is about all.

In the Plextor M5S equation we are still left with a very big variable that doesn't really allow us to complete the mathematical puzzle until we can fill in the blank space. That empty space is identified with the marker $. When Plextor gave us their MSRP they specifically warned us that the MSRP is "just a recommendation". When a company does that they are telling us in marketing terms, it isn't going to ever hit that high of a price. Given that the Plextor M5S does not ship with the same software suite, desktop adapter bracket and the warranty is cut to three years instead of five, I don't think the MSRP numbers are anywhere close to what we'll see in August when the product arrives in e-tail warehouses.

Until we see real-world pricing figures, we're going to say spend your money on a M3 or M3 Pro. If you are using your purchase for a desktop, then the older model is a much better choice anyhow since it ships with a desktop adapter bracket. The M3 class of drives also comes with a better warranty and premium Toggle Mode flash that we feel is superior to IMFT 25nm. That recommendation is based on the M5S hitting the high MSRP which is very close to where the M3 Pro 256GB is right now at Newegg.

If the Plextor M5S hits the market where the LSI SandForce drives are now, $1 per GB or less, that is another story all together. Even at $1 per GB, the Plextor M5S still has to compete with LSI SandForce and the Crucial m4. Plextor has neutered the M5S of all of the add-on bits that make the line attractive to start with. At equal pricing with LSI SandForce drives, I still don't think this model is going to compete very well.

We'll post an update when we have actual pricing in a couple of weeks.

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