Thunderbolt: How devices affect each other on a daisy chain

Macworld by James Galbraith

The Macworld Lab has a small collection of Thunderbolt peripherals, and we thought we should put them to work to answer questions we had about connectivity and how devices affect performance.

After testing dozens of scenarios, we found that—for the most part—the two available bi-directional 10Gbps channels in the MacBook Pro (Late 2011) were more than able to keep up with the demand of multiple storage devices on a Thunderbolt daisy chain. However, if you add multiple displays to that chain, the throughput of some drives can be severely limited.

(For your reference: The iMac (Mid 2011) uses the same Light Ridge Thunderbolt controller as the MacBook Pro, but the iMac has two Thunderbolt ports and offers up to four bi-directional, 10Gbps channels. The MacBook Air (Mid 2011) uses an Eagle Peak Thunderbolt controller that allows for two bi-directional 10Gbps channels.)

Drives in a daisy chain

The Thunderbolt drives involved in our testing were the Promise Pegasus R6 RAID array, the LaCie Little Big Disk Thunderbolt Series SSD, and the LaCie Little Big Disk Thunderbolt Series 2TB hard drive. read more...