OWC Express 1M2

This guide is intended only for macOS computers. The product in this guide may support mobile devices and Windows computers, however this guide is only written to support macOS computers. If you are seeking support for something other than macOS, please contact Tech Support.

Before going through any of the specific issues it is best to confirm the computer being used with the device is compatible. At the time of writing this guide the Express 1M2 has the following requirements for its host computer:

Minimum macOS: 10.13

Computer connection: Thunderbolt 3 or later, USB-C, and USB4

To ensure that your files are protected and to prevent data loss, we strongly suggest that you keep two copies of your data: one copy on your OWC Express 1M2 and a second copy on either your internal drive or another storage medium, such as an optical backup, or on another external storage unit. Any data loss or corruption while using the OWC Express 1M2 is the sole responsibility of the user, and under no circumstances may OWC, its parents, partners, affiliates, officers, employees, or agents be held liable for loss of the use of data including compensation of any kind or recovery of the data.

1. Ensure the Express 1M2 is connected to the computer and the computer is powered on
2. We want to confirm whether the Express 1M2 is mounting first. The Disk Utility application needs to be opened. From Finder, click on the “Go” menu in the menu bar and then select “Utilities.” Disk Utility will be found in the window that opens. If available, click on the “View” menu in the menu bar and select “Show All Devices.” On the left sidebar the Express 1M2 should be listed.
   1. If it is seen, the LED dimmer switch in the Express 1M2 needs to be checked.
      1. Eject the Express 1M2, unplug the USB cable, and then open the Express 1M2 following section 2.2 of the Product Manual.
      2. Note: First generation Express 1M2s do not have a LED dimmer switch. Please skip down to step 3 "If it is not seen in Disk Utility"
      3. With the USB port facing away, the LED dimmer switch will be found in the middle-left side of the Express 1M2. Check what position the switch is in
         1. In the top position, closest to the USB port, the white LED should be as bright as possible
         2. In the middle position, the white LED will be in a dim brightness
         3. In the bottom position, furthest from the USB port, the white LED should be off
      4. If the white LED is not working and the switch is in the off position, move it to the On or Dim position. Connect the USB cable to the Express 1M2 and check to see if the LED is working now
         1. If it is still not working and the Express 1M2 is under warranty you may request a return for warranty work
3. If it is not seen in Disk Utility
   1. Try a different USB-C cable, preferably one that is known to be functional.
   2. If the Express 1M2 is still not listed, try a different USB-C port on computer. Also, if an adapter, hub, or dock is being used, if possible, bypass the hub, adapter, or dock.
   3. If other bus‑powered devices are connected, eject and disconnect them.
      1. Reconnect the Express 1M2 and check if it powers on.
      2. If this resolves the issue, the Express 1M2 requires sufficient power and we recommend using a powered hub such as the OWC Thunderbolt Hub or OWC MiniStack STX for best results. Visit our KnowledgeBase for more info on this.

1. Make sure the Express 1M2 is connected to the computer.
2. There is a setting in macOS that will not show external drives on the desktop, this is typically enabled by default.
3. We want to confirm the Express 1M2 is properly mounting first.
   1. On the Mac click on Finder located on the dock, this will open a Finder window if one was not already open. Navigate up to the “Go” menu in the menu bar and select “Computer.” Within, the Finder window the Mercury Elite Pro’s volume(s) will be listed.
   2. If it is not mounting, you’ll want to skip down to the Express 1M2 is not mounting or will not mount section
4. If the drive is there, we can enable the drive to show on the desktop by clicking on the Finder menu and then choose “Settings” (on older OSes it may be called “Preferences”). Under the General tab we need to check the “External disks” under the “Show these items on the desktop:” section.

Note: This section is intended for Express 1M2 enclosures that have drives installed. If a drive has not been installed yet, please see the product manual for steps on installing the drive in the enclosure

1. It is important for us to make sure we are only working with the Express 1M2, so unmount and disconnect any other drives that are connected to the computer.
2. Make sure the Express 1M2 is connected to your computer, if possible, connected directly to the computer (do not use a hub, dock, or adapter). If the white LED on the front is not coming on, first work through The Express 1M2 is not powering on. The white light is not working. section above.
3. The Disk Utility application needs to be opened. From Finder, click on the “Go” menu in the menu bar and then select “Utilities.” Disk Utility will be found in the window that opens.
   1. If available, click on the “View” menu in the menu bar and select “Show All Devices.” On the left sidebar the Express 1M2 should be listed.
   2. If the Express 1M2 is not listed.
      1. Unplug the Express 1M2 and try a different USB-C cable, preferably one that is known to be functional. Plug in the Express 1M2 and check to see if it shows in the left side bar again.
      2. If the Express 1M2 is still not listed, unplug the Express 1M2 and try a different USB or Thunderbolt port on the computer. Also, if an adapter, hub, or dock is being used, if possible, try a different adapter, hub, or dock.
         1. If the Express 1M2 continues to not be listed, if possible, try connecting the Express 1M2 to another computer. If the Express 1M2 works on the new computer, but not the original computer please contact the computer manufacturer for assistance in troubleshooting the computer’s USB or Thunderbolt port.
      3. If the Express 1M2 is still not seen and the Express 1M2 is under warranty you may request a return for warranty work
   3. If the Express 1M2 is listed on the left sidebar. Below the Express 1M2 the volume name will be indented.
      1. If the volume name is correct, click on the volume name, and then click on the “Mount” button in the upper right of the window.
      2. If the drive still does not mount or the volume name is not correct, try running First Aid.
         1. On the left side pane of Disk Utility find the Express 1M2. Select the lowest disk icon on the hierarchy of the drive.
         2. Click on the “First Aid” button and then click on the “Run” (on older macOSes it might be “Repair Disk” button). When the repair is complete review the results. If there is any entry that states something was fixed, click the “Done” button and click the “First Aid” button again and run through the process once more. Repeat this process working up the disk hierarchy, running first aid on the remaining disk icons. Once complete click on the volume name and then click on the “Mount” button in the upper right of the window.
         3. If a First Aid fails, try running it once more. If it continues to fail, please have a screenshot of the results, and then contact Tech Support.

1. It is important for us to make sure we are only working with the Express 1M2, so unmount and disconnect any other drives that are connected to the computer.
2. The Disk Utility application needs to be opened. From Finder, click on the “Go” menu in the menu bar and then select “Utilities.” Disk Utility will be found in the window that opens.
   1. If available, click on the “View” menu in the menu bar and select “Show All Devices”
   2. On the left sidebar the Express 1M2 should be listed. Click on the top level (left most justified icon). On the right side of the window, the capacity of the Express 1M2 will be listed.
      1. If the capacity is only slightly lower than expected (e.g. 1TB showing as 960GB) this can be normal due to built-in over-provisioning. Please contact Tech Support if there are questions or concerns remaining.
      2. If the capacity shows 33KB, 36KB, 1.08GB, or 1.2GB. This is generally a sign the drive has failed (not the Express 1M2 enclosure).
         1. If the Express 1M2 came with a drive installed and is under warranty, a request to return it for warranty work can be submitted.
         2. If the Express 1M2 is out of warranty or was a 0GB DIY enclosure, the drive should be replaced.
      3. For any other capacity concerns please contact Tech Support.

1. There are many factors that can affect the transfer speed of drives. Just to name a few: How a drive is connected to the computer. The type of files being transferred. The type of drive the data is being transferred from and being transferred to. In the case of SSDs (all Express 1M2), if and how large of a cache it has for writes. In most cases where drive performance comes into question there is nothing wrong with the drive. Most of the time for drive performance concerns there is a realignment of performance expectations needed.
2. The Express 1M2 can function through a variety of connections which can impact its maximum performance. Depending on the drive installed, when it comes to writing information to the Express 1M2, the amount of data being written can also impact performance. This is due to the cache mechanism found in the SSD. When the cache becomes full, write performance can have a notable drop. Note that read speeds are not impacted by the cache.
   1. With the Express 1M2 powered on and connected directly to the computer, we will want to open System Information. From Finder, click on the “Go” menu in the menu bar and then select “Utilities.” System Information will be found in the window that opens.
   2. Click on the “Thunderbolt/USB” section in the left sidebar. In the top section find “Express 1M2” and click on it. In the bottom section find the “Link Speed:” it should say “Up to x Gb/s”
      1. On Apple Silicon (M1, M2, M3, M4, M5, etc) computers x should be 40 Gb/s. This is the ideal connection for the Express 1M2 and will give the best performance possible.
      2. On Intel Apple computers or MacBook Neos x should be 10 Gb/s. This connection type will be the performance bottleneck of the Express 1M2
      3. If it reads “Up to 480 Mb/s” then it is only working at USB 2 speeds.
         1. If a MacBook Neo is being used, be sure to use the rear USB-C port (closest to screen hinge). The rear USB-C is USB 3 capable of 10 Gb/s while the forward USB-C is USB 2 capable of only 480 Mb/s.
         2. This generally means a USB-C charging cable is being used instead of a USB-C or Thunderbolt data cable. Please try another USB-C or Thunderbolt cable. After changing cables, within System information click on the File menu and select "Refresh Information". If the link speed is still showing "Up to 480 Mb/s" please contact Tech Support.
   3. To gauge the performance of a drive our preferred benchmarking tool to recommend is the free application, AJA System Test Lite. Please download and install AJA System Test Lite.
      1. If we want an accurate measurement of the true performance of the Express 1M2 it needs to have no data on it or very little data. With the computer powered on and the the Express 1M2 connected, it should sit idle for at least 10 minutes before running AJA system test. This will ensure the cache in the SSD has settled from any previous transfers.
         1. If possible, backing up the data on the Express 1M2 to another drive and then erasing it is recommended. If you have any questions or need help with this process, please contact Tech Support. This will give us the best numbers to compare to OWC’s baseline benchmarks
      2. Open AJA System Test Lite from the Applications folder.
      3. The settings OWC most often uses for the Express 1M2 are:
         1. Under the Resolution menu select “4096x3112 4K-Full”
         2. Under the Test File Size menu select “64 GB”
         3. Under the Codec menu select “16bit RGBA”
      4. Under the Target Disk select the name of the volume for the Express 1M2.
      5. Click the “Start” button. The test will begin, which can take a few minutes to complete.
      6. Based on the connection:
         
         1. As previously mentioned, results may vary due to a variety of reasons. If the numbers are lower than expected please contact Tech Support. Please have a screenshot of the test results ready.
         2. Up to 10 Gb/s: Writes should be between 800-1000 MB/s; Reads should be between 800-1000 MB/s
            
         3. up to 40 Gb/s: Writes should be between 2600-2950 MB/s; Reads should be between 2650-3050 MB/s

• The OWC Express 1M2 is not compatible with the front (1) USB-C or (1) USB-A ports of a Sony Playstation 5.
• The OWC Express 1M2 can be used with the back (2) USB-A ports of a Sony Playstation 5.
• Sony provides additional details regarding extended storage requirements through the support article USB Extended Storage on PS5 Consoles.