[citation][nom]CaedenV[/nom]thunderbolt is a medium that allows for multiple interconnect protocols to be transmitted over the same wire. It can send PCIe, it can send DP, it was supposed to be able to send USB 1/2/3, as well as Ethernet, all over the same wire... but we have not seen that happen over the copper version that was released.The external PCIe will be cheaper and easier because it will be hosted directly by the mobo chipset, or the CPU by tapping into already existing hardware. Chip makers will not have to add a new and expensive tech to the device, the connection will just siphon off lanes that are already there. And because it is already standardized and cheap technology it will be easier and cheaper to implement. Finally it will be an open standard that multiple manufacturers can adopt. Thunderbolt (as much as I love the idea) is made and operated by Intel, and Intel wants to charge a premium for it. Until there are multiple chip makers who can make it, then it will continue to be too expensive... and when multiple chip makers can make it then Intel will be the only one worth buying (much like their network interfaces) because nobody can do quality like intel, but at least the price will come down.[/citation]
Read http://www.tomshardware.com/reviews/thunderbolt-performance-z77a-gd80,3205.html Thunderbolt can externalize anything. It just has to have the controller. It is external PCIe. External USB 3.0 and ethernet are possible but unlikely because they are already on the mobo.
From a practical standpoint, external PCIe may cheaper, but it's pointless from a performance standpoint http://en.wikipedia.org/wiki/PCI_Express#External_PCIe_cards. Everything is limited to a PCIe 1.0 x1 connection. The new ExpressCard standard (v2.0) ups bandwidth to slightly more than PCIe 1.0 x2, which still isn't that fast compared to TB (PCIe 2.0 x4 uplink). Plus ExpressCard only lets you connect a single device. It's one and done after that. For a mobile user, Thunderbolt is the way to go. Worse, you can't count on EC to be available. I'm already seeing Ultrabooks with TB. It makes sense because it doesn't require a lot of space. EC requires more space, hence it will be a greater rarity now that TB is out.
It looks expensive now but be patient. TB is something you will want. Many people need to look past the role Apple played. It clearly is a performance oriented technology that opens up a whole new world, especially on the mobile side.
Cheers,
Andrew Ku
Tom's Hardware.com