GRAPH LEGEND
LaCie LBD TB2 = LaCie Little Big Disk Thunderbolt 2.0 (two internal 512G PCIe flash blades in RAID 0 set)
Pegasus2 SSDs = Promise Pegasus2 R4 Thunderbolt 2.0 Diskless 4Bay (four 6Gbps TransIntl SwiftData SSDs in RAID 0 set mounted using Sonnet Transposer adapters)
Akitio Duo = Akitio Neutrino Thunder Duo dual bay 2.5" Thunderbolt 1.0 enclosure (dual 6Gbps OWC Mercury Extreme SSDs in RAID 0 set)
LaCie LBD TB1 = LaCie Little Big Disk Thunderbolt 1.0 (dual 6Gbps OWC Mercury Extreme SSDs in RAID 0 set)
Pegasus2 HDDs = Promise Pegasus2 R4 Thunderbolt 2.0 Diskless 4Bay (four Seagate Constellation 4TB HDDs in RAID 0 set)
CalDigit T3 = Caldigit T3 triple bay 3.5" HDD Thunderbolt 1.0 enclosure (three HDDs in RAID 0 set)
G|DOCK ev = G-Technology G|DOCK ev two-bay Thunderbolt 1.0 dock designed for G-DRIVE ev 2.5" HDD modules (in RAID 0 set)
All enclosures were connected to a 2013 Mac Pro MD878LL/A Desktop. All enclosures required an AC adapter. (In about a week we will feature a collection of bus powered Thunderbolt storage devices.)
SIMULATED 4K VIDEO CAPTURE and PLAYBACK
We used AJA System Test to test file level sequential transfer speed of a 16GB test document. It also simulates capture and playback of a 4096x2160 10-bit RGB video. (HIGHEST number means FASTEST in Megabytes per Second.)
PERFORMANCE INSIGHTS
Manufacturers often trumpet the theoretical transfer rate of Thunderbolt 1.0 (10Mbps aka 1164MB/s) and Thunderbolt 2.0 (20Gbps aka 2384MB/s), but the real world transfer rate is lower -- often much lower -- depending on the kind of drive(s), the number of drives, the RAID configuration, the model of Mac, Thunderbolt interface overhead, etc. The graphs above illustrate the real world transfer speeds as well as the dramatic variance.
If you want your Thunderbolt 2.0 storage to transfer faster than 1375MB/s, you will need to stripe multiple, high speed, storage devices over multiple Thunderbolt 2.0 busses -- which is what we did in the article featuring up to three LaCie Little Big Disks (Thunderbolt 2.0) bridging up to three Thunderbolt 2.0 busses of a 2013 Mac Pro.
If maximum transfer speed is not critical (as in backup or archiving), for $599 you can purchase the CalDigit T3 (Thunderbolt 1.0) with 3TB of HDDs, or for $499 you get the LaCie Little Big Disk Thunderbolt 1.0 with 4TB total of notebook HDDs, or for $599 you can have the LaCie 2big Thunderbolt 2 with 6TB of HDDs.
Some of the Thunderbolt storage enclosures can be ordered EMPTY, allowing you to use HDDs and SSDs you already own. Some examples include the Akitio Thunder Duo (Thunderbolt 1.0) for $299, the Akitio Thunder2 Quad for $499, the OWC ThunderBay IV (Thunderbolt 1.0) for $459, and the the diskless Pegasus2 R4 (Thunderbolt 2.0) for $699.
Be sure to count the total cost when comparative shopping. For example, the diskless Pegasus2 R4 with four 250G 6Gbps SSDs (totaling 1TB) and the 2.5"-to-3.5" adapters will come to at least $1329. The Little Big Disk 1TB Thunderbolt 2.0 with factory installed flash blades (and a much smaller footprint) is prices out at a slightly lower $1299.
This round-up of multi-drive Thunderbolt enclosures is representative but, by no means, exhaustive. We have yet to benchmark multi-drive Thunderbolt enclosures from Other World Computing, Areca, and Western Digital. Also here is a review of the DataTale SMART 4-bay Thunderbolt RAID by Jeremy Wilker.
(In about a week we will feature a collection of bus powered Thunderbolt storage devices.)