James Galbraith over at Macworld has written up a fairly in-depth article on how multiple Thunderbolt devices daisy chained together affects performance of each device in the chain.
[quote]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.[/quote]
The article focuses on multiple scenarios for your Thunderbolt daisy chains, and then measures performance. Included in the study: drives in a daisy chain, drives and one display in a daisy chain, an iMac with two displays and three drives in a chain, as well as a couple of other scenarios.
It’s a good read if you’re interested in Thunderbolt and where we’re heading with the technology. It looks like it can pretty much handle anything you throw at it.
Read Thunderbolt: How devices affect each other on a daisy chain over at Macworld.