Problems with MX300 2TB SATA SSDs on a Mac

Kilobyte Kid

Problems with MX300 2TB SATA SSDs on a Mac

What to do with my 15-month-old 2 x MX300 2TB SATA SSDs?

 

I have them in an OWC ThunderBay 4 enclosure as external drives for a 2017 iMac using OS X 10.13.4. I was using them as a RAID 0 pair, but it started crashing the computer. (I isolated to crashes to the RAID 0 set and an OWC rep confirmed that a failing drive in a RAID 0 set can cause the computer to crash.) I tested both drives using Drive Genius's Physical Check feature and both gave an error "A possible hardware error was encountered while checking Crucial_CT2050MX300SSD1 Media. (Failed to read 131072 bytes at 105367470080. (22)) Check did not complete successfully." The locations of the failed bytes were slightly different between the drives but both gave consistently the same error. Both drives give the same problems whether they are in the ThunderBay or an external USB3 enclosure, so it is not an enclosure problem.

 

I borrowed a Windows 10 laptop and was able to update the firmware to the current version on both using the Crucial Storage Executive. My Mac can't read the SMART status of the drives, but the Windows laptop could and both SSDs are claimed to be in good health though there have been errors. The lifetime remaining is 99% on one and 100% on the other. I did the Power Cycle on both drives. Same Drive Genius error persists. I then decided to test the drives and wrote the drive full without problems (the speed slowed down a lot towards the end).

 

What to do now? Can I trust these SSDs to hold important data?

 

9 Replies
JEDEC Jedi

Re: Problems with MX300 2TB SATA SSDs on a Mac

Frankly, you should never 'trust' any drive in any condition to hold important data.  Make sure it's always backed up. Smiley Happy

 

Seriously though, can you post up the smart data. The 'good health' generally refers to the wear level and not errors.  Some 'errors' are fine (CRC corrected ones and udma ones).  Some are bad (like reallocations)

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Kilobyte Kid

Re: Problems with MX300 2TB SATA SSDs on a Mac

Naturally, everything is backed up in multiple ways.

 

Here are the error related numbers from the SMART prior to the current write test (drive 1 / 2):

- Raw Read Error Rate: 196 / 110

- Reallocated NAND Block Count: 78 / 43

- Reported Uncorrectable Errors: 48 / 99

- Reallocation Event Count: 78 / 43

- SMART Off-line Scan Uncorrectable Errors: 3 / 2

- Write Error Rate: 10 / 35

- Ultra-DMA CRC Error Count: 0 / 0

 

Are these numbers good / bad?

 

JEDEC Jedi

Re: Problems with MX300 2TB SATA SSDs on a Mac

Yes, please post the SMART Attributes from your SSDs.

 

With the MX300 series, they are using a newer type of NAND technology and unfortunately current TLC SSDs slow down during non-stop writing.  Before putting these SSDs back into production, I would suggest performing a Secure Erase on them which will reset them to a factory like condition for performance.   You do need to connect them to an internal SATA controller (using AHCI mode) or an eSATA controller  in order to perform a Secure Erase.

 

As for monitoring your SSDs in the external enclosure when using OSX, you need to install a special SCSI driver to allow access to the SMART Data.    DriveDX provides a signed binary driver which can be downloaded separately if you wanted to use another app to monitor the SMART Attributes while using the latest versions of OSX.

 

Most SMART Attributes do not reset so they will always show the accumulated values & previous errors.  The "Current Pending Sectors" value should reset once a bad block has been successfully reallocated.   With the pre-M0CR060 firmware it is sometimes necessary to perform a Secure Erase to get the blocks reallocated.   Some SMART monitoring apps will continue to report a failing SSD because they are treating the SSD like a hard drive because they see non-zero values for some attributes which for a hard drive usually indicates imminent failure.   SSDs are a little different.   As long as you are not seeing a large increase in Reallocated Sectors/Blocks  in a short amount of time you are probably Ok.

Kilobyte Kid

Re: Problems with MX300 2TB SATA SSDs on a Mac

Thanks! Which other SMART attributes do you want to see, in addition to the ones I posted above?

 

I have neither internal SATA controller nor eSATA controller available, so the Secure Erase is not going to happen, unfortunately. I'll have to do without.

 

I'll try that OS X driver for SATA, though they talk of USB / Firewire enclosures and this is Thunderbolt -- not sure if that makes a difference. Hope it works!

 

 

 

JEDEC Jedi

Re: Problems with MX300 2TB SATA SSDs on a Mac

Very glad you are keeping good backups!

 

As long as the Uncorrectable Errors are not still increasing and the "Current Pending Sectors Count" is zero you should be Ok.   If not, then you will need to perform a Secure Erase on the SSD in order to correct it or it would need to be RMA'd.

 

Please let us know if the SCSI driver also works for Thunderbolt as well.

Kilobyte Kid

Re: Problems with MX300 2TB SATA SSDs on a Mac

Plugged the drives into the Windows 10 laptop and here are the SMART attributes after writing the disks full:

 

Drive 1:

- Raw Read Error Rate stayed at 196.

- Reallocated NAND Block Count stayed at 78.

- Reported Uncorrectable Errors went from 48 to 66.

- Current Pending ECC Count stayed at 0.

Write Error Rate stayed at 10.

Ultra-DMA CRC Error Count stayed at 0.

 

Drive 2:

- Raw Read Error Rate stayed at 110.

- Reallocated NAND Block Count stayed at 43.

- Reported Uncorrectable Errors stayed at 99.

- Current Pending ECC Count stayed at 0.

Write Error Rate stayed at 35.

Ultra-DMA CRC Error Count stayed at 0.

 

Are these good / bad?

 

Haven't tested OS X the driver yet.

 

JEDEC Jedi

Re: Problems with MX300 2TB SATA SSDs on a Mac

Please post all of the SMART Attributes for Drive 1 as you indicate the Uncorrectable Errors are still increasing (make sure to remove your SSD serial number if it is shown).   Since you didn't post a complete list of attributes, I'm assuming you are using the command line to view them?  If so, append the following to whatever command you used so it will save the results to a file:  "  >   smart-results-drive1.txt".    This will redirect the output of the command to a text file instead.

 

 

Example:

smartctl   -a    /dev/sda    >   smart-results.txt

 

 

Attribute #197 Current Pending Sector is also one we need to see reset to zero.  If drive#2 has this attribute at zero then drive 2 is probably Ok.  Feel free to post its complete list of attributes.

Kilobyte Kid

Re: Problems with MX300 2TB SATA SSDs on a Mac

I was checking the SMART attributes on another computer, the Windows one, hence I wrote only some of them. I could try installing that OS X driver when I get a chance. 

 

My Mac doesn't have that smartctl command.

 

JEDEC Jedi

Re: Problems with MX300 2TB SATA SSDs on a Mac

DriveDX & SmartReporter provide a GUI interface for checking SMART.   You can also install the command line only version from here.    When installed I believe the command line only version is located in /usr/local/sbin/smartctl.    The ReadMe file should have the information.