Question: are thunderbolt 1 and 2 the same?
Answer: It turns out that the main difference between the two Thunderbolts is that version 2 has channel bonding and full DisplayPort 1.2, for full 4K video support. Whereas Thunderbolt 1 has 4 independent 10 Gb/s channels, Thunderbolt 2 combines these to give 2 20 Gb/s bidirectional channels.