Promise Pegasus2 R2+ Review

The Promise Pegasus2 R2+ ($749 for 6TB) is a versatile desktop-class external hard drive for both Macs and PCs, with a built-in two-bay RAID array. It combines the speed of two drives to give you added throughput and 6TB of storage. The "plus" in its name refers to the third drive bay, which comes with a media card reader installed, but that can be swapped out for optional accessories, like a solid-state drive (SSD) Reader pod. The Pegasus2 R2+ ( at Amazon) is not quite as blazing fast as our Editors' Choice for high-end, desktop-class external drives, the LaCie Little Big Disk Thunderbolt 2 , but it is still worth serious consideration for local backups via Apple's Time Machine and for use when quickly transferring large files from one computer to another.

Design and Features
The Pegasus2 R2+ is built into a black, metal box measuring about 5.3 by 7.3 by 9.8 inches (HWD). At 13.5 pounds, it's somewhat heavy. The RAID array's two drive sleds (Promise calls them pods) are readily accessible from the front panel, without the locks seen on other RAID arrays like the 8TB CalDigit T4 RAID ( at Amazon) . (While locks help secure drive sleds from prying fingers, they can also slow down drive replacement.) It's easy to remove either drive sled in seconds. They're hot-swappable in RAID 1 mode, but I wouldn't recommend removing them when they're in the default RAID 0 mode, as that could lead to data loss.

A removable CF/SD card reader pod occupies the Pegasus2 R2+'s auxiliary drive bay, which is located above the other two bays. You can remove the card reader and use it externally with an included USB 3.0 cable. You can also replace it in the third bay with an SSD Reader pod ($49), a 1TB HDD pod ($169), or a CFast 2.0 Reader pod (no pricing announced as of this writing). This gives you some flexibility while using the RAID array for your Time Machine backups or for keeping large file libraries always available.

Swing the drive around, and you find two Thunderbolt 2 ports, one USB 3.0 port, and the jack for the Power cable. The power supply is internal, so you won't have to find a spot for an external power brick, like on the CalDigit T4 RAID and the 12TB LaCie 2big Thunderbolt 2 ( at Amazon) . The Thunderbolt 2 ports can be used simultaneously, to daisy-chain the drive to a Thunderbolt display or another Thunderbolt-equipped hard drive. The USB 3.0 port has to be used alone, however, so you can't connect the USB port and the Thunderbolt port at the same time.

Two 3TB hard drives in a RAID 0 array yield a 6TB capacity, which is halved if you reformat the array to RAID 1. The 6TB capacity is solid, suitable for video scratch files or millions of photos. It's certainly spacious enough for months' worth of backups, and the array is also useful for holding large media libraries or for use as a work drive on your projects. The Pegasus2 R2+ is formatted for HFS+ out of the box, which is native for Macs running OS X 10.8 or later. You can reformat the drive for Windows PC use, but you need to download and install the necessary driver from Promise's website.

The Pegasus2 utility is also available for Macs and Windows PCs on its website. I was able to monitor the array's status, reformat drives, and check drive temperatures in the utility when the Pegasus2 R2+ was connected to an Apple iMac 21.5-inch with 4K Retina display( at Amazon) via Thunderbolt 2, but not when it was connected via USB 3.0, as the latter doesn't support the auxiliary drive bay. The drive comes with a two-year warranty.

Performance and Cost
The Pegasus2 R2+ was a fast performer in our tests using the Thunderbolt 2 interface. It scored quite well on the Blackmagic Disk test, which measures throughput speeds, at 374MBps read and 332MBps write. It lagged a bit behind the Caldigit T4 RAID, which scored more than 500MBps on the same test in each direction. The Pegasus2 R2+ performed similarly to the LaCie 2big Thunderbolt 2 (404MBps read; 358MBps write), and it outscored the 6TB LaCie d2 Thunderbolt 2 ($679.90 at Amazon) (208.7MBps read; 210.6MBps write). That said, the LaCie Little Big Disk Thunderbolt 2, our Editors' Choice for high-end, desktop-class external drives, is the champ, with 1,135MBps read and 1,099.1MBps write speeds, thanks to its internal SSDs, though you will have to pay just under $1,300 for that performance.

The Pegasus2 R2+ has a $749 list price, which translates into about $0.12 per gigabyte. Single-mechanism drives like the 6TB LaCie d2 Thunderbolt 2 are a much better value at about $0.08 per gigabyte, and the higher 12TB capacity of the LaCie 2big Thunderbolt 2 also comes to $0.08 per gigabyte. The CalDigit T4 RAID is more flexible with four drives, but it is more expensive, at about $0.20 per gigabyte. The LaCie Little Big Disk Thunderbolt 2 is priced dearly at $1.29 per gigabyte, but its SSDs give you blazing performance that justifies the cost, especially if you deal with a lot of mission-critical data.

Unfortunately, the Pegasus2 R2+'s performance on our tests over USB 3.0 is more consistent with slower USB 2.0 drives. It scored 41MBps read and 38MBps write on the Blackmagic test. Also, as I mentioned before, the Pegasus2 utility couldn't monitor the drive's status when connected via USB. Consider using the Pegasus2 R2+ over USB 3.0 only when you have to transfer data to a system that lacks a Thunderbolt port, like most Windows laptops or the Apple MacBook .

Conclusion
The Promise Pegasus2 R2+ is a speedy RAID drive that offers some flexibility, thanks to its extra drive bay and USB 3.0 connectivity. If you need a large-capacity backup drive, then it's a capable, versatile option that delivers plenty of utility in its design and features. However, the LaCie Little Big Disk Thunderbolt 2 remains our Editors' Choice for high-end, desktop-class external hard drives, thanks to its blazing speed that fully utilizes the Thunderbolt 2 interface.

Best Hard Drive Picks

• The Best External Hard Drives for 2020
• The Best Rugged Hard Drives and SSDs for 2020
• The Best External Hard Drives for Mac in 2020
• The Best Wireless Hard Drives for 2020
• More Hard Drive Reviews
• More from PROMISETechnology

Further Reading

• Early World Backup Day Sale: All-Time Low Prices on Storage Devices From WD, SanDisk
• How to Combine Multiple Hard Drives With Windows' Storage Spaces
• Deals: 4TB WD Elements Hard Drive, Lowest Price on Apple AirPods
• Seagate Will Ship 18TB and 20TB Hard Drives in 2020
• How We Test Hard Drives