Review: Acasis Thunderbolt 4-bay NVMe SSD enclosure (EC-3901)

Review unit provided by ACASIS

The ACASIS EC-3901 is a 4-bay NVMe SSD enclosure that supports Thunderbolt 4 and 3. Price at the time of review is USD 299.

Keys selling features would be the support for (software) RAID, fast transfer speed, cooling fan and daisy chain support. This product is made for those who need large storage capacity with fast transfer speeds, such as for 8K or RAW video editing.

Things included

• The enclosure
• 4x rubber stoppers for the SSDs
• 4x thermal paste
• 4x SSD plastic holders
• 50cm Thunderbolt 4 cable
• Power cable (plug options available)
• 96W power adapter
• User manual

If you don't need that much storage, you can consider the much smaller ACASIS TBU405ProMax 2-bay Thunderbolt NVMe SSD enclosure which also has more ports.

The reason why the EC-3901 is bigger than expected is due to the empty internal spaces designed intentionally to let air pass through the whole unit. This air flow design helps cool the four SSDs within more effectively.

Design looks beautiful. Build quality is extremely solid with the whole body made with aluminium.

The front has a big power button and status lights for individual SSDs and activity. The status lights for individual SSDs did not work on my review unit for some reason even though the SSDs work fine.

This enclosure will not power on or off together with the computer.

On the other side, we have the barrel power port, a 40Gbps USB-C port that connects to the computer, another 40Gbpz USB-C port for daisy chaining with other external storage devices. The USB-C ports do not support power delivery and do not output video.

The tool-less design is very convenient. The cover can be pulled off and you can install the SSDs, and apply the thermal paste.

Unfortunately for this review, I only have two NVMe SSDs to test so I can't test the full potential of using four NVMe SSDs.

These are the four different RAID types that are supported:

• PM mode (Win, MacOS, Linux)
• RAID 0 mode (MacOS, Linux)
• RAID 1 mode (Win, MacOS, Linux)
• LARGE mode (Win, MacOS)

The descriptions above are from the product page.

To learn more about the different RAID types, visit this Wikipedia page.

Which RAID type to choose depends on your workflow, the type of work you do and your risk tolerance. Personally for me, I would go with RAID 1, or either RAID 0 (speed focus) or LARGE MODE (which sounds like JBOD) and have another external storage for backup.

The RAID you get is software RAID. To configure the RAID, you'll have to rely on your OS. There are no RAID configuration instructions provided in the user manual.

For the tests below, the RAID types were configured with MacOS.

Speed test

For RAID 0, I measured 2600 MB/s write and 2200 MB/s read. This is fast enough to write and read 12K DCI 60 Blackmagic RAW or ProRes 422 HQ videos.

You get the fastest speed with RAID 0, but there's no backup so if any drive fails, all you data will be gone. An external backup is required.

For RAID 1 (mirror), I measured 1300 MB/s write and 2500 MB/s read. This is still pretty fast and offers one backup.

Downside here is you only get half the storage capacity.

This is JBOD and I measured 2100 MB/s write and 2200 MB/s read. Performance is slightly lower than RAID but better than RAID 1.

I would categorise the risk here to be similar to RAID 0.

Conclusion

This product works as advertised. If you need huge storage capacity with fast file transfer speeds, the ACASIS EC-3901 is certainly the Thunderbolt enclosure to consider.

The ACASIS EC-3901 is available from ACASIS online store