Cinema Display 20" - seems to work with 2 rather than 3 cables attached

[katewes]

The Apple 20" matte, silver-frame Cinema Display has three cables: a DVI cable, Firewire and USB.

According to the Apple instructions, all three need to be connected to the MacBook Pro's ports.

I used a DVI-to-MiniDisplay Port to connect the first DVI cable to the MBP's Mini-Display Port.

I connected the USB.

However, I did not connect the Firewire cable (because I didn't have a Firewire converter).

And yet, the Cinema Display seems to work fine with just 2 out of the 3 cables connected.

Why does Apple require all 3 cables to be connected, and am I potentially causing problems to the hardware? Or I am good to go with just 2 cables connected?

 

[Gav2k]

You only plug the usb and FireWire in if you want to use the port replicator on the back of the display.

 

[katewes]

You only plug the usb and FireWire in if you want to use the port replicator on the back of the display.

Thanks. So if I want the port-replicator, do I need to connect both the USB and Firewire, or will just one of those suffice?

 

[Gav2k]

USB will enable the USB ports and FireWire will enable the FireWire ports

 

[katewes]

USB will enable the USB ports and FireWire will enable the FireWire ports

Thanks. That makes so much logical sense. It's a pity that the Apple instruction manual did not explain that so clearly. The manual just said plug it in, without explaining what would be the result of plugging in the various cables.

 

[Gav2k]

That's what forums are for. To ask simple questions and get a simple answer back.

 

[katewes]

That's what forums are for. To ask simple questions and get a simple answer back.

Gav2K, you wouldn't happen to know if two such Cinema Displays -- with DVI cable -- can be attached to a mid-2012 MacBook Pro?