Mac Pro ATI 5770 with 3 monitors - what active adapters needed? I just bought a Mac Pro 2010 with an ATI5770 that has 2 x Mini Display Port (DP) and 1 x DVI.

The current configuration is as follows:


Mini DP A > passive HDMI adapter > 1920 LCD
Mini DP B > passive HDMI adapter > 1920 LCD
DVI > passive DVI to HDMI adapter > 1920 LCD


In this configuration, only two out of the three monitors will work at any given time.  From reading up on the topic, I understand that I'll need at least one active adapter in order to get all three monitors going together.

What is the minimal number of active adapters I need? i.e. do I need one or two, and on which port(s)? If that matters.

A recommendation for suitable non-Apple adapters would also be appreciated.
Confirmed: for this to work you need two (not just one) active adapters on the Mini DisplayPorts.  When shopping around, the adapters may also be referred to as Eyefinity compatible.  You don't have to buy genuine adapters - I am using two of the cheaper ones.