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How Ultrabook Performance Degrades Over Time with a Samsung TLC SSD

Kannon Yamada 03-07-2015

Have you noticed your Solid State Drive (what’s an SSD? How Do Solid-State Drives Work? In this article, you'll learn exactly what SSDs are, how SSDs actually work and operate, why SSDs are so useful, and the one major downside to SSDs. Read More ) suffering from slipping performance? If Samsung made your drive, it probably employs “Triple Level Cell” (TLC) NAND memory modules. A bug afflicts most–if not all–TLC drives. Fortunately, Samsung made a fix available for one of their drives to Windows users.


The problem: After 9-40 weeks, the SSD’s legendary speed can fall beneath even platter-based hard drives. After delays and failure, Samsung now claims it eliminated the bug with its latest firmware update.

On the downside, this update can function only on Windows or OS X systems. For those with Linux, you might update the drive from a Windows or Mac computer; although Linux users suffer from another deal-breaking issue with TLC memory.

What Is TLC memory?

Before Samsung’s invention of Triple Level Cell solid state memory, two kinds of memory dominated consumer and enterprise markets: Single Level Cell (SLC) and Multi Level Cell (MLC) memory.

SLC offers performance advantages at the expense of price and storage capacity. MLC memory offers cheaper costs while storing twice as much data per cell. Triple Level Cell (TLC) stores three times as much data as SLC and offers even cheaper costs to manufacture than MLC.

All flash memory comes with the disadvantage of limited write endurance – the more data written to memory, the faster the drive wears out, leading to its eventual failure. While flash memory can take a tremendous amount of writes before dying, manufacturers oftentimes void the drive’s warranty after a fixed (and very low) number of writes.


Unfortunately, unlike SLC and MLC, TLC memory suffers from an even lower write endurance, although this limitation only impacts those with overly stringent warranties.


How do I know if I have a TLC Drive?

There’s no comprehensive list of drives afflicted by the bug. This proves especially problematic for Ultrabook owners, who may not know whether TLC NAND inhabits their device. The surest method (in my experience): Check in Windows Device Manager and locate the entry under hard drives.

First, go to Device Manager:


device manager

Last, go to Hard Drives:

finding the name of the drive in windows



Then search the Internet for the name of the drive, including the term TLC. In my case, I would search for PM851, including the term TLC.

search for pm851

Users can also test their device’s read speeds for signs of decline. However, it seems that all TLC drives decline over time. The speed at which they decline centers around the production process, or how small the individual memory cells are. 19nm cells decline in speed after the data inhabiting the cells reaches 9 weeks. The older 21nm cells decline after 40 weeks.

For those interested, currently hosts a tool custom designed for testing read speeds relative to age, which is evidence of the bug. I ran the application (after malware-scanning it) and the results strongly suggest that the Samsung PM851 SSD (in most Ultrabooks) suffers from the bug.


overclock tool run on pm851

You will notice that older files are read more slowly than newer ones, on average.

A Brief History of Buggy TLC SSDs

Samsung’s lack of transparency compounds matters. At first, Samsung claimed the bug afflicted only the 840 EVO line of SSDs. However, subsequent drive speed readings indicated the Samsung 840 (but not the Pro line) suffered from the issue. Later on, reports emerged that the PM851 SSD used in most Windows Ultrabook Dell XPS 13 2015 Review and Giveaway The XPS represents the pinnacle of laptop design in 2015, and it's the best bang for your buck out of any laptop we've ever seen in the $800 price range. Read More s may also suffer from the problem.

The most recent rumors suggest that perhaps even the Samsung 850 EVO line, which employs V-NAND TLC, also suffers from performance issues. If true, then the sluggish performance may relate to electron decay and current leakage, a shortcoming exacerbated by TLC’s storage of 3 bits per cell.

Here’s a partial list of drives probably afflicted the by bug:

  • Samsung 840
  • Samsung 840 EVO
  • Samsung PM851 (M.2 form factor, limited to Ultrabooks)

Samsung hasn’t yet announced fixes for all these drives, yet. In fact, it seems their updated firmware includes only the 840 EVO line, despite the problem’s proven (and unacknowledged) existence on the 840. Of particular interest: The MP851 M.2 form factor SSD inhabits many Ultrabooks (what’s an Ultrabook? What Is An Ultrabook & Can It Succeed? [Technology Explained] Remember when the word laptop described virtually every mobile computer on the market? The choices were certainly easier back then (because there was simply less choice available), but today there’s a far wider variety including... Read More ), including the Lenovo Yoga Pro, the Microsoft Surface, and the Dell XPS series (and a lot more).

To my knowledge, none of these manufacturers pushed out Samsung’s fix yet, although Dell’s latest firmware update was released in April of 2015, making it the latest firmware update available. If you feel like rolling the dice, you can download and install the firmware update here. It probably won’t resolve the issue. It also may end up causing serious damage, if you do not have a compatible system.

angles dell xps 13

Applying Samsung’s TLC Fix for the 840 EVO

The fix only works on Windows systems. To install it, you must download the Magician software and update your drive’s firmware. Unfortunately, Samsung’s Magician is not available to those using M.2 form factor Ultrabooks.

Samsung provided a series of firmware upgrades, the first of which failed to resolve the issue. The second firmware upgrade requires more explanation. Essentially, Samsung’s firmware upgrade rewrites each bit stored on your hard drive, imperceptibly when your computer rests.

While this method maintains the SSD’s peak read performance, it will incur additional wear and tear. This additional wear and tear will void Samsung’s warranty far earlier than expected on the drive. Also, because TLC’s maximum write endurance falls substantially short of MLC drives, the fix falls short of user expectation.


Keep in mind that even TLC memory offers great resistance to memory writes, so the fix won’t break your drive anytime soon. Even so, consider disabling hiberate on SSDs Disable Hibernate On Your SSD For Warranty Purposes Killing your SSD only requires a bit of laziness. You can preserve your warranty and extend your SSD's lifetime by turning off hibernation. We show you why & how to do it. Read More .

Linux Concerns

Note that if you own a Linux system, a bug exists which can destroy your data. The problem extends from Samsung’s failure to properly implement TRIM (what’s TRIM? Why TRIM is Important to Solid State Hard Drives? [Technology Explained] Read More ) for use with Linux systems. An additional bug can actually destroy a Samsung laptop, if users install Linux, although the issue may have already been corrected as of the publication date of this article.


While Multi Level Cell (MLC) memory’s reliability ranks high, Samsung’s TLC lacks the same reputation. It seems that Samsung rushed TLC to market before performing proper validation testing. As a result, TLC–and possibly its successor V-NAND TLC–possess serious bugs that Samsung hasn’t fully resolved yet.

The simplest solution is to avoid any products that include TLC NAND memory until the problems get ironed out. Those owning an 840 EVO will need an immediate answer. You may want to consider installing the fix, despite the increased writes to your drive. For everyone else, you will need to wait.

Have you noticed decreasing performance of your SSD?

Related topics: Computer Memory, Solid State Drive, Ultrabook.

Affiliate Disclosure: By buying the products we recommend, you help keep the site alive. Read more.

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  1. Barry Jackson
    January 22, 2017 at 12:04 pm

    Like anybody reading this didn't know you could run linux on a raspberry pi. What a shitty title

    • Kannon Yamada
      January 22, 2017 at 12:06 pm

      You may have responded to the wrong article. The title of this article is "How Ultrabook Performance Degrades Over Time". This is one of the reasons we need to ditch infinite scroll combined with collapsed comments. It makes it way too easy to accidentally respond to the wrong article. My apologies Barry.

  2. Anonymous
    July 10, 2015 at 7:03 am

    the problem with Samsung drives in linux is still permanent that also includes 850 evo & pro.
    to limit this problem disable trim under Linux and or Unix system.
    particular Btrfs, ext3, ext4, JFS, ReiserFS, XFS this are have problems with trim enable.
    this problem has been ignored by Samsung on all there drive 840 & 850 Evo / Pro and M.2 SSD drives.

  3. Anonymous
    July 7, 2015 at 1:34 pm

    So, I wanted to share this article with some of my colleagues, but there are no Share Buttons anywhere on the page...wha.??

    • Anonymous
      July 17, 2015 at 1:52 pm

      You must be running an adblocker that blocks the share button located at the top of this article.

  4. Anonymous
    July 6, 2015 at 11:50 pm

    The 840 EVO fix can be applied by Windows, OS X and Linux users. For non-Windows users, there is an ISO file that can be downloaded and then run.
    There are of course other complications that could arise if the user is using the drives in a RAID array.

    PCPer has been following the story from the start. Here is the link to one of their articles where they have the information for the standalone ISO.

  5. Anonymous
    July 6, 2015 at 11:30 pm

    I think these things are real trash. First off they won't copy a system drive even though they lead you to believe they do with their special software. If you read the fine print it won't copy any file that is in use. (NT user profiles for example).

    But even considering that I am pretty good at dealing with windows and it's issues I could not make this drive work in my Asus G73Jw to save my life.

    Just a word of caution if you're considering swapping out an older mechanical drive in favor of this supposedly faster and cooler operating tech. If you decide that you want to use this technology I would advise you to do it when you're willing to re-install windows from scratch or when you buy a new computer.


  6. Anonymous
    July 6, 2015 at 2:39 pm

    Sadly, I bought Samsung SSDs for all of my desktop Windows and Mac machines, due to Samsung's strong reputation for those products. Very disappointing, to say the least....

    • Kannon Yamada
      July 6, 2015 at 3:45 pm

      Do they have verified TLC or are some of them MLC? I think 840 PRO is MLC. There's a few other drives as well that aren't afflicted by the bug.

      With any luck they end up pushing out the fix to all TLC drives. The ramped up writes is unfortunate, but shouldn't affect anything other than the warranty.

      • Anonymous
        July 7, 2015 at 3:31 pm

        "With any luck they end up pushing out the fix to all TLC drives." -- not holding my breath. Switching back to Intel-based drives...

  7. Anonymous
    July 4, 2015 at 3:28 am

    Point of order: M.2 SSDs can also be found in high-end desktop/server Intel Z97, X99 and C612 motherboards and M.2 slots are also present on > 1 year old high end business grade notebooks such as Lenovo Thinkpads and HP Elitebooks. They're not just an Ultrabook technology.

    • Kannon Yamada
      July 4, 2015 at 7:45 pm

      That's true. I thought the PM851 was sold as an OEM part to Ultrabook vendors, but it would make sense if it was also sold in some small form factor systems. I believe they have both mSATA and PCIe variations of the drive, but am not sure. Both of these include TLC NAND, so they both should suffer from the bug.

      • Anonymous
        July 4, 2015 at 9:53 pm

        It's more or less the best of breed M.2 option, so plenty of enthusiast systems have been built with those PM851 SSDs.

        OEM part or not, I've bought a few dozen of them on
        Wear leveling on Samsung drives has always been a bit suspect, but if you're chasing top specs you have to remember that the second place option is something like 15% slower overall. That's huge for high end parts, even if it's erased within a few months of normal use.

        • Kannon Yamada
          July 4, 2015 at 10:11 pm

          Isn't SM951 already out? It's OEM only at present, but I've heard that it was being sold in small numbers from some of the usual retailers. It also probably has TLC in it, but it's overall a big jump up on the PM851 in both iterations.