Copyright 2010 - K.S. Studios - All rights reserved
Model No. SST-DS221B (black)
Enclosure material Aluminum
Color Black
Power requirement
5V 2A power adapter
Operating system support Windows 2000/XP, Vista, 7
Mac OS 9.x (Apple USB support 1.3.5 and greater) and Mac OS 10.1, 10.2, 10.3, and 10.4
Mac：G3 processor or greater
Computer with eSATA or USB 2.0/1.1 interface
PC
HDD size support
2.5” hard drive x 2
HDD interface support
SATA hard drive
Minimum System Requirements
Windows 2000/XP, Vista, 7
Mac OS 9.x (Apple USB support 1.3.5 and greater) and Mac OS 10.1, 10.2, 10.3, and 10.4
Mac：G3 processor or greater
Computer with eSATA or USB 2.0/1.1 interface
PC
Enclosure interface eSATA (Max. 3Gbits)
USB2.0 (Max. 480Mbits)
HDD capacity support 1TB Hard Disk and below
Net Weight 370g±10g
Dimension 168mm(L)x120mm(W)x28.3mm(H)
The DS221 is SilverStone's newest mobile storage product, a dual 2.5" hard drive raid enclosure capable of running in three modes; JBOD, Raid 0, and Raid 1. The drive enclosure has connections for USB 2.0 (480Mbits) and eSATA (3Gbits). The exterior of the DS221 is a stunning brushed aluminum with silver accents. The unit is very light (about 1.5lbs with drives installed) but has a sturdy feel. Most of us have a need for some sort of portable storage device, whether its to move large amounts of data between multiple locations or just hooking up to a media center PC to stream video files. While there are a multitude of devices that make this task easy, few have the functions that the DS221 offers in such a compact chassis. Does SilverStone offer more than the mainstream? Read on for the full review.

Specs

SilverStone DS221 Dual Bay HDD Raid Enclosure

The DS221 is a compact, easily configured Raid device that's sure to find a place in many enthusiasts homes. The enclosure has a power adapter that has to be carried around if you decide to transport your data, but it is portable enough to take with you. We were very impressed with the overall responsiveness and speeds the DS221 offers. The Raid functions are nice, but we have to wonder who really has two spare 2.5" drives laying around that they can use with the DS221? Most users will have to purchase the two drives, and with the cost of 3.5" terabyte drives these days, you might be better off getting a full size enclosure that can also be used with a single drive if desired. We would really like to see SilverStone release a 3.5" tool-less enclosure just like this one (hopefully using the new USB 3.0 spec). If you're in the market for an extremely portable raid device that is easy to set up and manage, you just might find the DS221 to be the perfect fit.

2/23/10 -Keith Soreghen-

Packaging

Conclusion

For those that need a refresh on Raid terms:
  • JBOD (just a bunch of disks) - Data is spanned into one logical partition with no fault tolerance.
  • Raid 0 (striping) - Data is distributed across multiple disks ( two in this case) to improve speed. No fault tolerance. If one disk fails, the array is lost.
  • Raid 1 (mirroring) - Two disks have identical data. Fault tolerance is present. If one drive fails, the array can be rebuilt from the good disk.

The descriptions below are specific for the DS221 in terms of number of drives as the device can only hold two total hard drives:

Raid mode
Number of disks
Capacity
Performance
Safety
Application User
JBOD
2
Full two disks
Same as one disk
No
Capacity user
Raid 0
2
Two disk capacity based on lower capacity HDD
Highest
No
Performance user
Raid 1
2
50% of two disk capacity
Better than one disk
High
Security user

SilverStone always packages their products nicely and the DS221 is no exception. The enclosure and stand are packaged seperately from the accessories to prevent things from flopping around during shipping.

Accessories

The DS221 comes with the power adapter, USB to mini USB cable, eSATA cable, a plastic stand for the drive, and the user manual. The user manual is only three pages of information in various languages. The PDF manual on SilverStone's website is the same. A brief explanation of different raid modes is given as well as the DS221 specs. The instructions for operating the enclosure are simple, but more on that in a minute.
The exterior is very nice brushed aluminum with silver accents. The two hard drive doors are easy to open and close and have a smooth action. The top and bottom have vent holes to help cool the drives. The device barely gets warm during operation. The back of the DS221 is where the controls and connectors are. These include the mode selector switch, mini USB 2.0 port , eSATA port and the DC 5V plug. The look and feel are super high quality. SilverStone gets high marks for aesthetics.

Exterior

The Setup

Instructions for using the DS221 are brief because there really isn't much to it at all. Install the drives, select a raid mode, plug in the data cable, then plug in the power. Once the DS221 is prepared with drives and the proper cables are connected, the only thing left to do is to press the reset button on the front of the unit and format the drives through the operating system's disk management section. We tested the DS221 using two of Western Digital's 320GB Scorpio Black hard drives. These are their premium 7200 rpm laptop drives and should give some pretty good performance for our tests. These drives are installed with the labels facing to the right (verify drive orientation by peeking into the drive bays to see how the connectors are facing). Slide the drives in by hand until they clear the door, then use the door to push the drives in the rest of the way until seated. The door will click shut when closed properly. The installation is completely tool-less and takes just a few minutes to get it ready to go.

The included eSATA cable will allow the best connection for the DS221. Its nice to have the option to use a USB cable to transfer data, but you won't get great speeds using the aging interface.

Testing

All three Raid modes were tested using both the USB connection and the eSATA. HDTune Pro 4.01 was used to benchmark the hard drives. Everything worked well until we tried to switch Raid modes. The reset button alone did not do the trick. The DS221 would only change modes by first disconnecting the data cable from the computer, flipping the mode switch on the back, pressing the reset button, pulling the power cable, plugging the data cable back in, and finally, plugging the power cable back in. Yanking the power cable while the drives are spinning doesn't seem like it would be very good for the hard drives, but the DS221 does not have a dedicated on/off switch.

To test, we connected the DS221 to the front panel eSATA connector on our computer which is plugged in to the motherboards SATA port. The device was detected by the bios, but would not show up in Windows Vista's disk management until the computer was rebooted. This method was verified to work when switching between the three Raid modes using the eSATA cable. Windows 7 fared better at detecting the eSATA arrays. Disk management would immediately show the array without having to reboot the computer, though the DS221 still had to be power cycled to change Raid modes.

Both operating systems detected the USB arrays without issue. The Raid modes were all detected immediately and functined as expected. It seems that the USB connection will display the Raid mode that is currently running while the eSATA connection will not. When connected using the eSATA cable, the device will show up as a generic partition instead of listing it as a Raid partition. It still runs in Raid, but just doesn't display it by title. This is a Windows issue, not an issue with the DS221.

Here are the benchmarks:

The DS221 eSATA port
The front reset button for resetting raid modes
WD 320GB Scorpio Drive
JBOD USB
Raid 0 USB
Raid 1 USB
JBOD eSATA
Raid 0 eSATA
Raid 1 eSATA
The highest numbers obviously come by utilizing the Raid 0 mode on the DS221 using the eSATA cable, but this method provides no data redundancy. If the safety of Raid 1 is what you're looking for, the speeds using the eSATA cable are still respectable. Overall speeds using the USB cable are on average with other external storage drives. We simulated a drive failure after setting up a Raid 1 array by pulling one of the drives from the DS221. After plugging the unit back in, we were still able to access the data on the remaining drive. The data would have to be backed up at this point and a new array created if a drive had actually failed . We also tried installing a single drive to see if the enclosure could be used without a Raid array, but the drive was not detected. In general, the DS221 has some nice features if you can get past its limitations.