Apple usb-c to HDMI seems to support 3840x2160@60

stormxu

macrumors newbie
Original poster
Jul 6, 2017
2
0
Champaign, IL
Just notice the updated instruction at https://support.apple.com/en-us/HT206587

says:

"With macOS 10.12 or later, MacBook (2015 and later) and MacBook Pro (2016 and later) support these resolutions and refresh rates over HDMI 1.4b using the USB-C Digital AV Multiport Adapter:

  • 4096x2304 at 48Hz refresh rate
  • 3840x2160 at 60Hz refresh rate (mirroring is not supported at this resolution)
"

Can anyone confirm this? Also what is the usb-A speed then? I am planing to buy a 3840x2160 monitor for my non-tb MacBook Pro 2017. If apple's dongle can support this, It would be great (no need to use a port to dp)
 

campyguy

macrumors 68040
Mar 21, 2014
3,415
932
HDMI 1.4 does not support UHD @60Hz. Apple's adapter is a passive adapter.

Consider an active adapter, one that supports HDMI 2.0 and, therefore up to UHD @60Hz. Accell Cables makes active adapters for both the mDP and USB-C port configurations to HDMI 2.0a.
 

MrX8503

macrumors 68020
Sep 19, 2010
2,269
1,571
That will not support 4K @ 60hz.

The problem is bandwidth. You won't find any multi adapters (that I know of) that will support 4K @ 60Hz unless it's TB3.
 

campyguy

macrumors 68040
Mar 21, 2014
3,415
932
TB3 carries DP 1.2, just like the MBPs all do going back years. DP 1.2 conveys plenty of relevant throughput/bandwidth for UHD @60Hz with the correct adapter. Like I wrote in my OP, Accell makes a mDP>HDMI 2.0 adapter that handles 4k @60Hz - I've got several in my offices for our displays waiting for Kaby Lake PCs and Macs…

Specifically, this adapter, under $40 - QED:
https://www.accellcables.com/products/mini-displayport-1-2-to-hdmi-2-0-adapter
Accell makes other adapters like this with different input interfaces, and their products are on the DisplayPort.org product portal unlike most of the junk out there. And, Apple's cables/adapters haven't gone through the certification process - Accell's relevant products have. Cheers.