NVMe External Enclosure

Allen Kuo (kwyshell)
4 min readJun 17, 2019


I am looking for a super fast USB disk as a replacement for my portable hard drive. The normal USB flash drives are not a good enough. See Tom’s Guide’s Best USB drives 2019 documentation, the fastest USB drive is about 400MBps Read/Write. This is not the ultra-fast portable drive I want.

Instead of looking for USB flash drivers, I find the new NVMe USB controller could be the only hope for me. The NVMe external enclosure installs a USB NVMe bridge controller so that you can install your NVMe M.2 2280 PCIe SSD to the external case and works like a USB flash drive.


Kingston Digital KC1000 NVMe PCIe 480GB SSD

To see if the performance of external enclosure is good enough, I moved my PC NVMe SSD to the NVMe cases. The KC1000 goes with the MLC technology memory and performance is about 2700MBps/900MBps Read/Write. The USB 3.1 Gen 2 owns the maximum bandwidth 10Gbps (about 1.2GBps). In theory, it would be good enough if we can get 1.0GBps Read/Write.

My three NVMe SSD Enclosures:

ORICO Aluminum, Sabrent USB 3.1 Aluminum Enclosure (Expensive) and ZEXMTE M.2 NVMe USB 3.1 Adapter (Cheapest).

ORICO Aluminum M.2 NVMe SSD Enclosure

ORICO Aluminum M.2 NVMe SSD Enclosure

Sabrent USB 3.1 Aluminum Enclosure

Sabrent USB 3.1 Aluminum Enclosure for M.2 NVMe SSD in Gray (EC-NVME)

ZEXMTE M.2 NVMe USB 3.1 Adapter

ZEXMTE M.2 NVME USB 3.1 Adapter M-Key M.2 NGFF NVME to USB

Unstable Unstable Unstable

Compare to USB 3.1 Gen 1 5Gbps, USB 3.1 Gen 2 owns 10Gbps bandwidth. To maximum the performance, you should install the NVMe enclosure to USB 3.1 Gen 2 10Gbps Port. Simply install the USB disk using the PC’s TYPE C port.

After testing my new 3 NVMe USB cases, I get very bad result. It’s unstable. The performance is not good and you cannot pass all SSD tests. The installed USB disk will be randomly disconnected.

USB 3.1 Gen2 10Gbps is the root cause of this problem. It seems to be hard to keep the device to work with USB 10Gbps stably. Intel’s Thunderbolt 3 has 40Gbps bandwidth works well and stable but USB 10Gbps doesn’t. The HOST USB super-speed+ controller, USB cable and USB devices controller are all possible causes of this instability.

USB Host Controller

I have 2 motherboards and different USB 3.1 Gen 2 host controllers.

AMD USB 3.10 Controller 1.10

According to my test, the AMD version can be successfully completed at least 3 times in 10 tests. But neither can operate stably.

Device Control Chip

All my three NVMe SSD enclosures are all using the same JMicron JMS583. This is different from my expectations. The reason why I bought the cases was because ORICO did not perform well, so I bought others for testing, but I didn’t expect it to be the same chipset.

--------------------- USB Device Descriptor ---------------------bLength                  : 0x12 (18 bytes)
bDescriptorType : 0x01 (Device Descriptor)
bcdUSB : 0x320 (USB Version 3.20)
bDeviceClass : 0x00
bDeviceSubClass : 0x00
bDeviceProtocol : 0x00
bMaxPacketSize0 : 0x09 (9 bytes)
idVendor : 0x152D (JMicron Technology Corp.)
idProduct : 0x0583
bcdDevice : 0x0204
iManufacturer : 0x01 (String Descriptor 1)
Language 0x0409 : "JMicron"
iProduct : 0x02 (String Descriptor 2)
Language 0x0409 : "External"
iSerialNumber : 0x03 (String Descriptor 3)
Language 0x0409 : "DD564198838A5"
bNumConfigurations : 0x01 (1 Configuration)

Although they use the same chipset, the PCB construction is different. In addition, the design of the external box also affects the overall performance. At full speed, the external temperature may be as high as 70 ° C / 158 ° F, so a good heat dissipation design is also an important indicator of stable operation.

USB Cable

I tried more USB CABLE and got a simple conclusion. First, you must confirm that your USB CABLE is USB 3.0 compliant. Then the shorter the lines, the better. The longer the line means the worse the line signal. Finally, be sure to buy a good quality line.

USB 3.0 Cable


Finally, The Sabrent USB 3.1 Aluminum Enclosure is the best enclosure for me. Now, I use the case with my AMD chipset and it gets the best performance and works very well.

If it doesn’t work anyway, try to use USB 3.0 GEN 1 or even USB 2.0.

AS SSD Benchmark

The KC1000 performance is about 2700MBps/900MBps Read/Write. After using the Sabrent external box, the performance is about 820MBps / 270MBps Read/Write. In other words, the overall performance is only about 30% of the original.