Hacker News Reader

Comment by neither_color | Hacker News Reader

>you can use two 4k monitors at the same time -which is impossible with the M1 MacBook Pro

I have two 4K monitors hooked up to a 14" macbook pro currently. I believe it's the air that only connects to one external display.

View on HN

According to the official documentation [1], the 13" M1 MacBook Pro also has this limitation:

  > If you're using a Mac with the M1 chip:
  > 
  > On iMac, Mac mini, MacBook Air, and 13-inch MacBook Pro, you can connect one external display using either of the Thunderbolt / USB 4 ports.

[1] - https://support.apple.com/en-afri/HT202351

Well, the 13” M1 MacBook Pro is basically the Air with a fan and more ports?

Yep, though that's really more of a question of chip: the M1 only supports two displays, for the laptop that includes the internal one (the Mini only supports two displays, and one only 4K via HDMI).

To be fair, several of my work laptops had a similar sentence in their user handbook, but two monitors were possible if you connected the wires before booting the laptop.

Really strange limitation, as it never scaled with bandwidth - so 4k 90+Hz was doable, but 2x 1080p60hz wasn't.

Some intel laptops (Ivybridge chips definitely, sandy Bridge probably) had such warnings because officially the chip couldn't support running three displays due lacking enough clock generators. Given the almost-analog nature of HDMI and naive LVDS, this meant trouble.

Thing is, Display Port has much more different physical layer derived from PCIE, and so connecting two displays by DP and running internal screen with LVDS worked just fine.

Reply on news.ycombinator.com