OWC Envoy Pro EX Thunderbolt 3 and Plugable TBT3-NVME2TB Portable SSDs Review

Miscellaneous Aspects and Concluding Remarks

The performance consistency for real-world applications was looked at in the previous section. We recently added a test to determine the effectiveness of the thermal solution for sustained workloads. After deleting the SSD volume, a fio workload was set up to write sequential data to the raw drive with a block size of 128K and iodepth of 32 to cover 90% of the drive capacity. The internal temperature, instantaneous write data rate, and total amount of data written in total till that point of time were recorded.

Sequential Write to 90% of Disk Capacity - Performance Consistency

Plugable TBT3-NVME2TB 2TBOWC Envoy Pro EX Thunderbolt 3 2TBDIY TEKQ Rapide - WD Black SN750 TB3 SSD 1TB (Win 10 1809)

The Plugable TBT3-NVME2TB tops out at 51C, while the OWC Envoy Pro EX climbs up to 58C. The TEKQ Rapide enclosure, however, is not able to keep up with the performance of the WD SN750, allowing the SSD temperature to climb up to 66C. It is likely that such a hot internal SSD would not pass Intel certification for Thunderbolt 3 SSDs, but that is clearly not a concern for DIY enthusiasts. On the other hand, vendors like Plugable and OWC have to pass certification, and may end up having to implement proactive throttling in the firmware of the SSDs used in Thunderbolt 3 enclosures. The performance under such a stressful workload is nothing to write home about for either the Plugable or the OWC SSD. Both show remarkably similar behavior - for the first 1TB of writes, the performance is pegged at around 140 MBps, and beyond that, it keeps oscillating between 50 and 120 MBps. The WD SN750 in the TEKQ Rapide, on the other hand, maintains a rock-solid 640 MBps throughout the workload even after the SLC cache rus out (with the older Windows caching policy, it is 1500 MBps+). The official response from Plugable regarding this behavior was as follows: "In order to ensure a positive user experience, Intel has strict thermal and power requirements NVMe media must meet for use in bus-powered Thunderbolt 3 storage devices that we followed. We followed these guidelines to get Intel certification and provide the best experience for our customers."

The above exercise also allows us to determine the SLC cache size and/or the amount of data that can be written in one shot without a drop in the write data rate. The graphs below plot the transfer rate and the total data transfer amount from the start of the fio workload to the approximate timestamp at which the transfer rate shows a significant drop.

Sustained Writes - Characteristics

Plugable TBT3-NVME2TB 2TBOWC Envoy Pro EX Thunderbolt 3 2TBDIY TEKQ Rapide - WD Black SN750 TB3 SSD 1TB (Win 10 1809)

Both the Plugable and OWC drives have around 25GB of SLC cache, while the WD SN750 in the TEKQ Rapide has around 17GB.

Thunderbolt 3 host ports can supply up to 15W for downstream devices. M.2 NVMe drives do not consume that much power, but, we did take a fine-grained look at the power consumption profile for all three drives. Using the Plugable USBC-TKEY, the bus power consumption for the SSDs was tracked while the CrystalDiskMark workloads were processed. The workloads were set up with an interval time of 30s.

Drive Power Consumption - CrystalDiskMark Workloads

Plugable TBT3-NVME2TB 2TBOWC Envoy Pro EX Thunderbolt 3 2TBDIY TEKQ Rapide - WD Black SN750 TB3 SSD 1TB (Win 10 1809)

As expected, the power consumption profile for both the OWC and Plugable drives were similar - with the peak consumption being slightly south of 7W, and idling at around 2W. Our DIY configuration idled at around 2.5W, with peaks above 7W. Overall, the OWC and Plugable drives consumed lesser energy, albeit while delivering lower performance.

Support for TRIM is essential for flash-based storage devices in order to maintain long-term performance consistency. Since Thunderbolt 3 SSDs are seen as NVMe drives by the OS, TRIM support can be taken for granted. We used CyberShadow's trimcheck tool to confirm by using the following routine:

• Format the SSD in NTFS
• Load the trimcheck program into it and execute
• Use the PowerShell command Optimize-Volume -DriveLetter Z -ReTrim -Verbose (assuming that the drive connected to the storage bridge is mounted with the drive letter Z)
• Re-execute trimcheck to determine status report

Conclusions can be made based on the results from the last two steps. As expected, all three drives support TRIM.

TRIM Support

Plugable TBT3-NVME2TB 2TBOWC Envoy Pro EX Thunderbolt 3 2TBDIY TEKQ Rapide - WD Black SN750 TB3 SSD 1TB (Win 10 1809)

Moving on to the pricing aspect, Plugable is launching the TBT3-NVME2TB at $500, but, with a $100 discount on top. Even with a $500 price tag, the TBT3-NVME2TB is the most economical of the lot on a per-GB basis. Its post-formatted 2048 GB capacity gives it the edge, when compared with the 1920GB capacity of the OWC Envoy Pro EX Thunderbolt 3.

In summary, we would have liked better performance consistency for stressful writes from both the Plugable TBT3-NVME2TB and the OWC Envoy Pro EX Thunderbolt 3. However, given the price points, very few users may complain about that aspect. The thermal design for the Plugable drive is excellent, while the ruggedness of the OWC drive may make it attractive to certain market segments. By and large, the performance of the Plugable and OWC drives are equivalent, and users can make a purchase decision purely based on the best available deal at the time of purchase. On a general note, we are happy to see the appearance of economical Thunderbolt 3 SSDs in the market with high performance for real-world workloads.