The reference GTX 660 is equipped with 1 DL-DVI-D port, 1 DL-DVI-I port, 1 full size HDMI 1.4 port, and 1 full size DisplayPort 1.2. Like GK104 and GK107, GK106 can drive up to 4 displays, meaning all 4 ports can be put into use simultaneously.
The reference GTX 660 is equipped with 1 DL-DVI-D port, 1 DL-DVI-I port, 1 full size HDMI 1.4 port, and 1 full size DisplayPort 1.2. Like GK104 and GK107, GK106 can drive up to 4 displays, meaning all 4 ports can be put into use simultaneously.