If like me, you were wondering how the MacBook was going to run a UHD4K monitor out of its USB-C port, that only supports 5gbit/sec, this article from September 2014 on Anandtech explains it all. There’s a passthru of sorts for DisplayPort that allows higher resolutions than the 5gbit/sec of bandwidth would suggest. According to Apple’s specs, the MacBook supports up to DisplayPort 1.2, which is the same as all the current Macs. Thanks Anandtech, once again and thanks to @fowl2 on Twitter for bringing it to my attention.