My on-board Intel graphics from about 2 years ago lets me output to a pair of 4k displays. It's not going to win any awards for performance, but it is fine for watching videos.
My 10 year old MacBook which has Displayport but not Thunderbolt, can go up to QuadHD on Displayport, but only 1080p with my HDMI adaptor. So obviously, you should check the spec sheet, but I think pretty much anything should be fine if you just want lots of pixels.
Biting the hand that feeds IT
