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Many Windows Ultrabook Solid State Drives (what’s an SSD?) suffer from a crushing flaw. After approximately 9-40 weeks, their Samsung drive’s read speeds grind to a crawl, thanks to their Triple Layer Cell (TLC) memory modules. The problem also afflicts anyone with a Samsung 840 or 840 EVO SSD (or most drives using TLC).
Fortunately, a fix exists which restores much of the drive’s original performance.
What’s the Problem with TLC?
For me, the problem surfaced when I experienced poor performance on my Dell XPS 13, 2015 edition. A quick search led to a thread on Overclock.net, containing mention of a temporary fix. At first, uninstalling programs would cause a crash or take much longer than normal. As the problem worsened, the performance of older programs deteriorated.
According to PCPers, it appears that TLC SSD read speeds attenuate over time. Not all files suffer from the slow reads. Strange enough, if a file exists for less than 9 weeks, its read speed won’t deteriorate. But the older a file, the slower it gets.
How Did Samsung & the OEM Respond?
In response, Samsung updated the firmware for the Samsung 840 EVO, but not for any other drive affected by the bug. Worst of all, according to one of Samsung’s customer service representatives, no fix will arrive for any Original Equipment Manufacturer (OEM) drives, as these fall outside of warranty.
I contacted Samsung, regarding the issue. They had published, and then retracted, a fix for the issue on PM851 drives in 2014. I asked Samsung why they removed the fix for the problem, but left the instruction manual online. Their response, although prompt, failed to answer the question:
This is a OEM SSD not supported by us, does not have a warranty with us, and does not work with out software.
In other words, don’t count on them to fix the problem. Considering that a tremendous number of Windows Ultrabooks use Samsung TLC drives, that leaves a lot of us out in the cold.
I also called the laptop manufacturer, Dell. Dell offered more courteous help, but they claimed ignorance of the drive’s defect, despite the problem getting mentioned on their own support forums.
What Other Options Do Affected Users Have?
Without help from either Samsung or laptop manufacturers, what can we do?
Fortunately, thanks to the work of Puran Software, there’s a program called DiskFresh. DiskFresh appears to restore some of a TLC SSD’s performance, although it incurs additional disk writes, which may shorten an SSD’s life expectancy.
DiskFresh works by rewriting some of the data on the drive. This refreshes the files, although it will write an equal amount of data to your hard drive. To illustrate, if you have 32GB of data written to the drive, the program will write an additional 32GBs. This obviously is not a program you want running constantly in the background. Rather, you should configure the software to run every three to four months.
VirusTotal indicated that one of the companies, Blueliv, associated with Puran Software serves malware. However Puran Software registers green on Web of Trust (which is a must have Chrome extension). However, Google recently classified (and then promptly declassified) the site as a potential malware source, meaning its software might contain malicious code.
In this case, I’m certain the detection was a false positive. Both Blueliv and Puran Software don’t offer malware of any kind. We’ve even reviewed some of Puran’s other programs, such as Splitter, which can break a file into smaller parts.
After installation, run the program. DiskFresh offers several modes of operation: First, there’s refresh individual partitions. Refreshing a partition won’t write over free space, which will limit the amount of writers to your drive. Second, you can elect to refresh the entire “RAW” drive, which will write an amount of data equal to your hard drive size. For example, if you possess a 128GB SSD, choosing RAW mode will write 128GB of data to the drive.
I recommend choosing the option to refresh individual partitions. If it doesn’t work, you can try using the option to refresh the entire drive.
Testing Disk Read Speeds
An application, hosted over at OverClockers.net, called SSD Read Speed Tester tests for the TLC slow read bug. You can interpret the data by looking at the clustering of file read speeds and comparing these to the file’s age. The tool also generates a graphical depiction of your drive’s performance, relative to its age.
The chart generated by SSD Read Speed Tester displays disk read speeds on a two axis graph. The X-axis displays the age of each file. The Y-axis displays the read speeds. If you notice an unnatural number of files older than 9 weeks with slower than normal read speeds, then you suffer from the bug. If these slow speeds persist after running DiskFresh, you may have either improperly run the program or your disk issues originate from another cause.
If DiskFresh works, you’ll notice that your average disk read speeds will improve. Pay close attention to average data read speed, which displays at the bottom right side of the results page for DiskFresh. For example, here is the result of one of the earlier benchmarks, before running DiskFresh:
As you can see, the average disk read speeds fell short of the advertised maximum reads of the PM851 drive. A lot less. Most SSDs saturate the sequential read capabilities of the SATA 3 channel.
Here’s the results after running DiskFresh:
The average disk read speed skyrocketed from 158 MB/s to 392 MB/s.
Say Goodbye to TLC Memory
So, more or less, your TLC drive will lose a lot of its speed over the course of its lifetime. Refreshing Windows 8.1 or 10 also restores performance, but it forces users to reinstall their software. Samsung’s V-NAND appears to not suffer from TLC’s issues, but it hasn’t been on the market for very long and might suffer from a similar issue.
At the beginning of 2014, TLC drives came from only one source: Samsung. Since then, recent technological innovation from IM Flash Technologies (IMFT) led to XPoint memory, which represents a quantum leap in SSD technology.
Intel intends on releasing the XPoint in 2016. If it does, flash memory prices should begin a relentless tumble into oblivion. Anyone seeking to upgrade their hard drive should consider waiting a year and seeing what ripples XPoint makes in the industry.
Given the upcoming technology, TLC seems like a technological dead-end.
Have you encountered this issue and was DiskFresh able to fix it? Are you considering to upgrade your SSD to enhance performance?