How many devices does the Thunderbolt port support?
The Thunderbolt port supports daisy-chaining of up to 7 devices. Just like FireWire, you can connect one device to another via a simple Thunderbolt cable, up to three meters long. This information applies to the MacBook Pro Thunderbolt port – and it’s copper implementation of Thunderbolt (Yes, an optical version was already prototyped but the copper one hit the streets.)
Will Thuderbolt devices be slower when daisy-chained?
The devices will share the 10 Gigabit per Second full duplex bandwidth available.
This means approximately 750 Mb/second of the Thunderbolt Mac port / 7 devices – this would leave more than 100 Megabytes per second of average bandwidth per device. In a very bad case – using all of them together. This is a very inappropriate figure but just to give an idea – and full duplex (which was also in Firewire 800) means input and output data streams to the Mac do not share the same channel on the Thunderbolt interface, improving performance when using mixed type devices on the chain.