The wait for Thunderbolt-ready peripherals is over. Four months after the debut of Thunderbolt in Apple's revamped MacBook Pro lineup, storage devices that support Intel's new interconnect technology have finally arrived. And while these initial products carry a notable price tag, Macworld Lab's first tests show Thunderbolt offering a great leap forward in terms of performance.

On Tuesday, Promise Technologies announced the availability of the Pegasus R4 and R6. These external RAID systems, with either four (Pegasus R4) or six (Pegasus R6) drive bays, feature two Thunderbolt ports and range in price from £769 for an R4 with four 1TB 7200-rpm hard drives, to £1,399 for an R6 six 2TB 7200-rpm hard drives. The necessary Thunderbolt cable is not included with either unit, but is available from Apple for £39.

With the proper adapters, Thunderbolt has the ability to support many types of peripheral connections (including HDMI, USB, FireWire, Fibre Channel and more). In addition to storage devices, you can connect Mini DisplayPort displays, such as Apple's LED Cinema Display.

Our initial tests with the Thunderbolt-equipped 12TB R6 found that it is considerably faster than similar devices we've tested--devices that use FireWire, USB, or both. The R6 is Thunderbolt-only, so we couldn't isolate the performance differences of the connection by testing the R6 with a different interface. As a point of reference, we compared the R6 to another Promise RAID, the SmartStor DS4600 with four 1TB drives. The R6 and DS4600 were tested as RAID 5 devices.

We used two different systems to test the RAIDs: a 15-inch 2.2GHz Core i5 MacBook Pro with a 256GB solid-state drive and 4GB of RAM; and a 27-inch 2.7GHz Core i5 iMac with a 1TB hard drive and 4GB of RAM.

When connected to the iMac, the R6's AJA System Test read scores came in at 566MBps--6.8 times faster than the DS4600 using FireWire 800. Even more impressive was the R6's 644MBps AJA System Test write score, which is 11.5 times faster than the FireWire 800 scores of the DS4600.

Copying a 2GB file from the iMac's internal hard drive to the RAID was 30 percent faster on the R6. Copying the 2GB file from the RAID back to the iMac's internal drive was a little more than twice as fast on the R6 than on the DS4600 that used FireWire 800. Folder copy results were very similar to file copy test results. A low-memory Photoshop test using large files and the RAID as a scratch disk showed the R6 to be 37 percent faster than the DS4600.

When connected to the MacBook Pro (which has a slower processor than the iMac, but a faster internal SSD), we see that the R6's AJA System Test results are very similar to the results when the R6 is attached to an iMac. In our tests involving the 2GB file and 2GB folder of files, the R6 benefited from the solid-state drive in the MacBook Pro. Across the board in these tests, the R6-MacBook Pro/SSD combination outperformed the R6 attached to an iMac with an internal hard drive.

USB 2.0 and FireWire 400 are included for comparison's sake. Feel free to snicker at the more-than-20-times faster AJA System Test write speeds that the R6 posts over the DS4600 connected via USB.

Check back soon for more results, including eSATA, RAID 0, and reports on using Thunderbolt for both Target Disk and Target Display modes. Like Apple and Thunderbolt, we're just getting started.