The ASUS BP1AD will only support 2 independent displays at a time. It is likely a HW or BIOS limitation of the system. See page 31 and 72-73 of the attached users manual.
A workaround would be add a Display Link based port extender.
Intel Core i7 4770 (3.40GHz)
- 8GB DDR3 1TB HDD Capacity
- Windows 7 Pro 64 bit / Windows 8 Pro 64 Bit
- Intel HD Graphics 4600
- Certificated by Energy Star 5.2
- Support 2 Independent Displays
That is not the specs on this computer, (16GB DDR3, i5 Processor in this) though I'm fairly certain it's not going to make a difference. Either way, that's pretty stupid on ASUS' part...take a system that is more than capable of doing what we need...advertise is as "Intel HD Graphics 4600" without specifying any limitations...and then cut one-third of it off?
Sounds like ASUS has a problem misleading their customers.
Out of curiosity are you able to connect a HDMI and DVI display at the same time?
Yes, sir I am - that's what's odd about this. They're all ACTIVE..and they all WORK... just not all three at one times...which to me means the card is complete and functional..and after reading your response...I'm led to believe that ASUS did that...but I can't think of any logical reason.
You may want to contact ASUS to see if they have any information on this limitation.