Promise Pegasus R4 review: Promise Pegasus R4

The Pegasus R4 also supports RAID 0, 1, 50, 6, 60, and 10. It comes with WebPAM PROe software for Windows and Pegasus Utilities for Mac. You can use either program to manage the drive, including changing its RAID setup, viewing the status of each hard drive, and so on. In my testing, the R4 took a very short time to change from one RAID to another, just a matter of minutes. I did find that WebPAM PROe could only be used to manage the Pegasus drive that was directly connected to the computer and not the others in a daisy-chain setup. Pegasus Utilities, however, can manage multiple daisy-chained Pegasus units at a time. This is not a big deal, however, since most of us wouldn't be able to afford more than one unit anyway. Also, Promise says it will soon fix this with a new version of the WebPAM PROe software.

Furthermore, unless you want to change the RAID setup, you won't need to use the software at all and there's no setup process to fiddle with. All you have to do is plug the R4 in and it works immediately.

Performance
I tested the Pegasus R4 with a new custom-built test PC that uses Intel's new DZ77RE-75K motherboard, a Core i7 CPU, 8GB of DDR3, and a 480GB Intel 520 series SSD. This is a very fast computer using one of the fastest solid-state drives (SSDs) on the market. Still, the top speed of the SSD, which is 6Gbps, is slower than the ceiling speed of the Thunderbolt standard, which is 10Gbps. With this setup I experienced what consumers would find in real-world usage. I tested the R4 only in its default RAID 5 setup, since this is the most popular and recommended RAID for a drive of its type.

Like other Thunderbolt drives, the R4 was benchmarked with two sets of tests. In the first set, it was stacked up against internal drives, both traditional hard drives and SSDs. In the second set, it was compared with other external devices that use USB 3.0, USB 2.0, FireWire, eSATA, and, of course, Thunderbolt connections.

In the tests against internal drives, first, I timed how fast the Pegasus R4 performed when copying data from one folder on itself to another, meaning the drive had to perform reading and writing at the same time. In this test, the R4 was much slower than the R6, scoring just about 100MBps. The R4 was more than twice as fast at copying data from another Thunderbolt drive, the R6, now registering about 240MBps. It was still slower than the R6, though faster than most other Thunderbolt drives.

The second set of tests measures the Pegasus R4's performance against more traditional external storage drives. For these tests we copied data directly from the test machine's internal SSD to show what a typical user could expect from a single R4 unit. In this test, the drive scored very well at 150MBps and 171MBps for writing and reading, respectively.

While not as impressive as its bigger brother, the Pegasus R4's performance will blow any Windows user who hasn't experienced Thunderbolt before. The drive was rather noisy during operation, however, and you can feel the vibration coming from its internal hard drives. You might want to leave it on the floor rather than on top of a desk for this reason.

Unlike other Thunderbolt devices I've seen except for the Pegasus R6, the Pegasus R4 doesn't share power status with the host computer, meaning it won't turn off when the computer is off or sleep and turns back on when the computer is powered up. You will need to manually turn it on or off, so don't leave it too far away from your reach.

Data transfer speed, Thunderbolt vs. internal (in MBps)
(Longer bars indicate better performance)
Unit-to-unit  
Self-read and write  
Promise Pegasus R6 (RAID 5)
323.79 
192.53 
Plextor PX-256M2S
261 
162.03 
OCZ Vertex 3
260.71 
150.01 
Promise Pegasus R4 (RAID 5)
240 
100.5 
Crucial M4
235.51 
117.99 
LaCie Little Big Disk SSD
233.5 
141.69 
OCZ Agility 3
207.75 
101.67 
Patriot Wildfire
202 
99.72 
WD VelociRaptor 600GB
126.33 
58.05 
Elgato Thunderbolt SSD
121.96 
71.84 
Seagate Barracuda XT
115.71 
51.1 
WD VelociRaptor 300GB
112.59 
47.12 

Data transfer speed, Thunderbolt vs. external
(Longer bars indicate better performance)
Read  
Write  
Promise Pegasus R6 (RAID 5)
177.53 
210.5 
LaCie Little Big Disk SSD
186.8 
184.71 
Promise Pegasus R4 (RAID 5)
171.1 
150.47 
Elgato Thunderbolt SSD
168.97 
120.61 

Service and support
As with the R6, Promise Technology backs the Pegasus R4 with a two-year warranty for all parts except for the fan and power adapter, which are covered for only one year. This is a rather short time period for a storage device, especially one that costs thousands of dollars. On Promise's Web site, there's scant support-related information about its Thunderbolt-based products.

Conclusions
After more than a year of Thunderbolt being available exclusively for use with Macs, it's exciting that now Windows users can enjoy it. The Pegasus R4 marks the liberation of this superfast peripheral standard on the PC front. As a storage device, it will make a very good investment for anyone who can afford its premium pricing.

Don't Miss

 

ARTICLE DISCUSSION

Conversation powered by Livefyre

About The Author

CNET editor Dong Ngo has been involved with technology since 2000, starting with testing gadgets and writing code for CNET Labs' benchmarks. He now manages CNET San Francisco Labs, reviews networking and storage products, and also writes about other topics from online security to new gadgets and how technology impacts the life of people around the world.