Q: Will only mirror 2 Displays will not extend displays in 10.10.5
I have the latest Mac Air with 2 Dell U2414H daisy chained monitors. It will only mirror each monitor which is pretty useless. It will not extend the displays. The arrangement tab also shows 2 different size monitors when the settings are the same for each.
The worst part is they will only mirror when I have chosen to extend.
Mac mini (Late 2014), OS X Yosemite (10.10.5)
Posted on Dec 1, 2015 3:46 PM
Same situation with my 2015 MBA. I have 2 Dell U2414 displays, both of which support MST and DP 1.2
I can only get them to mirror, they will not daisy chain. I also tried to connect them to my 2014 MBP with the same result. The only way I was able to extend the displays was to connect each monitor to the thunderbolt/display port on my MBP. Obviously, this is not going to work with my MBA as it only has one TB port. I know the only other work around would be to run one display on the TB port and another from a USB port with an adapter, which in my opinion is a terrible solution as it ties up a USB port and is a mess on my desktop. From everything I've read, it is a limitation of OS X, not a hardware issue. I run Parallels with a Windows VM on my MBA and it sees both displays just fine with daisy chain using the one TB port on my MBA. What gives Apple? Why intentionally block DP third party monitors from working with OS X? Frustrating. The other frustrating thing is that there are no workarounds from what I can see-
Posted on Dec 17, 2015 2:02 PM
