Ugreen CM335

Ugreen CM335 review: A decent DAS for the price


Direct-attached storage (DAS for short) is a great way to expand your system capacity through the installation of a few drives. They differ from NAS in that there’s no OS, no networking ports, and you’re limited to just one device accessing the DAS at any given time. Today, we’re looking at the Ugreen CM335.

Why you can trust NAS Master

We’ve been testing and reviewing storage for 8 years.

Our in-depth reviews, guides, and buyer recommendations are only possible thanks to the vast knowledge and experience we’ve managed to accumulate over the years. We know just about everything there is to know about storage.

Find out more about the NAS Master team.

This is a two-bay DAS with support for RAID 0 and RAID 1, offering a few ways to store data. It’s an affordable DAS too with a capacity of up to 40TB using the aforementioned two bays. While you won’t be able to run virtualized environments or Plex Media Server, there’s a place for such a DAS in the office or at home.

Ugreen CM335

Ugreen UM335
Ugreen UM335. (Source: Ugreen)

The Ugreen CM335 is an affordable two-bay RAID DAS that can be used for quick storage deployment and transferring files between systems.

Bays2 (SSD/HDD)
Cooling1x 60 mm
Ports1x USB-C
  • Affordable price
  • Hardware switch for RAID 0/1
  • Supports up to 40TB capacity
  • Includes USB-C and USB-A cables
  • Somewhat loud operation
  • Cheaper build than competitors

Price, specs, and availability

A direct-attached storage enclosure like the Ugreen CM335 doesn’t have a long list of specifications since these devices are usually simple in nature. The Ugreen CM335 simply allows you to connect it to a PC for use as an external drive, using one of the available RAID modes.

The two 3.5-inch drive bays allows for a maximum capacity of up to 44TB, using the largest drives available today.

Design and features

The Ugreen CM335 is an inexpensive external enclosure, undercutting some of the competition. It’s clear to see how the design is slightly on the cheap side, but this is only noticeable when handling the unit. Measuring 261 x 235 x 177mm, the CM335 could fit on most desks.

If you’re planning to use 2.5-inch drives, especially SSDs, there will be a considerable lack of weight to the enclosure. It’s just 2.04kg without drives installed. As with any enclosure, you’ll find the two drive bays up front, alongside status LEDs.

The trays are easy to remove and lock into place, though they too feel a little on the cheap side. Ugreen includes all the necessary screws for installing drives, though these aren’t required for a 3.5-inch storage medium.

The rear of the Ugreen CM335 hosts a power input port, power button, reset button, a single USB-C port, and a RAID mode selector. The latter allows for the selection of one of a few modes, including RAID 0 (maximum capacity, no data protection), RAID 1 (mirrored for better data protection, lower capacity), Span, and PM.

Through the use of this physical switch, the Ugreen CM335 makes use of hardware RAID over a software solution, allowing for faster throughput at the cost of versatility.


You’re likely not going to run out of bandwidth with the Ugreen CM335. The enclosure uses a single USB-C connection with the capability of hitting up to 5Gbps. We were able to hit the maximum transfer speeds of SSDs and HDDs of around 475MB/s.

This is comparable to competitor DAS enclosures. You will notice a slight uplift in performance when running RAID 0, but this comes at the cost of no data protection. RAID 1 lowers performance slightly, but you are able to recover from a single drive failure.

We always recommend you keep more than one backup of all important data, however.


There aren’t as many DAS enclosures as NAS servers, but there’s still a good collection of units from reputable brands. TerraMaster is one such NAS manufacturer which also has a few DAS units for use in specific scenarios. We previously looked at the TerraMaster D3-400.

Compared to the Ugreen CM335, the TerraMaster D3-400 has an additional two bays for double the capacity of the CM335. It also looks a little more premium with its aluminum finish. Performance-wise, you’ll likely not notice much of a difference between the two DAS.

Should you buy the Ugreen CM335?

Who should buy this?

  • If you’re looking for affordable and simple storage with 3.5-inch or 2.5-inch drives.
  • If you’ve only a few systems that need sporadic access.
  • If you don’t need to store more than 40TB of data.

Who shouldn’t buy this?

  • If you want a NAS for running apps, network access, etc.
  • If you have multiple systems that require frequent access.
  • If you require more than two drive bays.

The Ugreen CM335 is a brilliant compact enclosure for direct access to up to two drives. With full support for hardware RAID and the choice between RAID 0 and RAID 1, it’s a great budget-friendly external storage box. Whether you’re transferring files or want to provide access between a few systems, the CM335 would be a great buy.

If you’re wanting to run more software and utilize more advanced features, a NAS is going to be the better buy over a DAS like the Ugreen CM335. It’s a basic enclosure that’s designed primarily for use with two drives to turn them into a single storage pool.

Ugreen CM335

Ugreen UM335
Ugreen UM335. (Source: Ugreen)

Ugreen’s CM335 has two drive bays, supports RAID 0 and 1, and can handle capacities up to 40TB. It’s ideal if you’re just storing a few files or frequently work between machines.

Richard Pinnock-Edmonds Avatar

Latest articles