Intel HD graphics introduced with Westmere (2010) supported dual displays, and then Ivy Bridge (2012) supported three displays on the iGPU. AMD's Llano (2011)

Intel HD graphics introduced with Westmere (2010) supported dual displays, and then Ivy Bridge (2012) supported three displays on the iGPU. AMD's Llano (2011) supported dual/triple(1) displays on release and Trinity(2012) brought support for up to four displays at once. (1)You could do triple displays on Llano, but it took a particular set of boards using Dual-Link DVI to drive two monitors IIRC.