I'm trying to create the most optimal setup for my first Macbook Pro Retina (Early 2013) I have a Dell 30" u3014 connected to it right now using DisplayPort, plus set to to 1.2. I have a 2nd monitor, old Dell 20" Ultrasharp, connected to the Macbook's 2nd thunderbolt via an Apple mini-DP to VGA adapter. Now, I'd like to just connect the old Dell 20" to the back of the Dell 30", using its displayport out to daisy chain. The displayport out is no mini, so I need a new cable. Do displayport daisy chains need to always use DP to DP to work? Or can the last monitor on the chain us a DP to VGA (active) cable, or DP to DVI (passive)?