by Mark Kidd

Icy Dock MB559U3S-1S Ultra Slim USB 3 & eSATA HDD Enclosure Review

Icy Dock’s new MB559U3S-1S portable USB 3.0 and eSATA enclosure is as much about how you use storage when you’re not on the go as is about providing a safe, thermally efficient housing for drives operating in the field. The MB559U3S-1S is a sound choice for a hard drive or SSD enclosure, but it’s true benefits come from a drive tray that is interoperable with a variety of other Icy Dock enclosures and RAID cages.

Portable storage technology is making it possible for professionals in a variety of storage-intensive fields to bring high-performance, high-capacity storage with them on the road, at the job site, or on location. At the same time, the amount of data being generated means that it is not just important to have access to bulk storage outside the office, but to be able to integrate that portable data storage into a smooth workflow back at the datacenter, digital studio, or home office.

The MB559U3S-1S’s true selling point is compatibility with the swappable tray system that Icy Dock uses with its MB453, MB454, MB455 and MB561 lines. Icy Dock offers the tray separately as part number MB559TRAY, which allows Icy Dock users to purchase as many trays as they have drives and simplify the workflow of transferring data between portable and desktop or server-based storage.

Video Overview


The MB559U3S-1S features a slim, fanless aluminum body that acts as a heatsink for the drive. At 1.16 lbs empty, this enclosure is reasonably light but shows that Icy Dock did not scrimp on aluminum. Its overall dimensions are 191 x 142.6 x 31.2 mm. The enclosure features four spring-loaded feet that pop out to support the drive in a vertical orientation. These rubberized feet provide more vertical stability than many drive enclosures, but the latch and spring mechanisms may not hold up to months or years of daily opening and closing. Though in our experience, vertical stabilizers that are not built-in tend to get lost by about that time anyway.

To remove the tray, one presses against a plastic slider, allowing the aluminum arm to pop free. Moderate pressure on the arm loosens the drive from the enclosure interface allowing the user to remove the tray. The trays are designed to accommodate 3.5-inch hard drives drives. Unlike some tray and caddy systems, this tray system is not designed to offer physical protection while drives are outside of the enclosure.

The back of the enclosure offers one eSATA port, one USB 3.0 port, a slot for a security cable, and a toggle power switch, along with the release button for the pop-out feet.


With eSATA offering the native speed of the drive, we shifted our focus to the USB3 connection on the Icy Dock MB559U3S with a 1TB Western Digtal Velociraptor. We used a standard IOMeter profile to measure both sequential and random access performance. The native sequential performance of the Velociraptor in our original testing measured 205MB/s read and write, with a speed of 141 IOPS read and 370 IOPS write with random 4K transfers. Testing through the Icy Dock enclosure's USB3 interface, we measured sequential performance of 205MB/s read, 201MB/s write, and random 4K performance of 144 IOPS read and 371 IOPS write. Basically, there was no loss in performance in sequential or random I/O activity through this enclosure when equipped with the WD Velociraptor.


  • Tray interoperability with other Icy Dock enclosures and RAID backplanes
  • Rugged aluminum construction
  • Handy pop-out feet


  • Relatively expensive for a single-drive enclosure
  • Tray system does not offer physical protection while removed from the enclosure


The MB559U3S-1S brings new value and functionality to the Icy Dock storage ecosystem, allowing customers that need portable access to their drives to simplify workflows and use one interoperable tray system. The MB559U3S-1S isn’t likely to bring new customers to Icy Dock, but it’s not intended to -- this product is designed to broaden the range of applications for Icy Dock’s drive enclosures and cages.

MB559U3S-1S at 

Discuss This Review