Apple has this support document about 4K display compatibilty. For my MacBook Pro (Late 2013), it says it can drive:
HDMI: 4K at 30Hz
DisplayPort (SST): 4K at 30Hz
DisplayPort (MST): 4K at 60Hz
It lists the following displays that are compatible to MST:
Sharp PN-K321, ASUS PQ321Q, Dell UP2414Q and UP3214Q, Panasonic TC-L65WT600.
Most of these are 2013/2014 models, and many manufacturers have newer models of these displays available now. However, most display specs don’t list SST or MST. Some of them hint at it by specifying “DisplayPort 1.2”, but without Apple listing more recent models, you’re left in the dark if a specific newer display really works with an older MacBook Pro. Most PC-centric review sites simply recommend to update the Windows Nvidia drivers, which isn’t very helpful for Mac users.
MST really is a hack that combines two virtual screens or streams that make up the full image. It was a transitional technology to bridge the bandwidth gap for 2013 computers to 4K displays. Even the 5K iMac pulls off a similar stunt internally to drive its display.
So, what I really wanted was a display that supports both MST and SST for my current, “old” MacBook Pro, and additionally a new Mac that I will buy when this MacBook Pro breaks.
A follower on Twitter helped me out with this problem, and recommended the Asus PB287Q, a very affordable 28″ 4K display that supports the Late 2013 MacBook Pro 15″ and also should support SST for newer Macs.
You’ll also need a Mini DisplayPort to DisplayPort cable. Some users report on the Apple Support Forum that they have trouble reaching 60Hz with some models, but I’d recommend trying another cable first. I got this and it appears to be working fine.
28″ is a good size. I was worried about getting a larger 31.5″ screen that would extend beyond the edges of my field of vision without moving my head. On the other hand, at 1:1 scaling, UI chrome naturally gets very small, just at the edge of what I can comfortably still read at 2ft from the screen, and this also is the minimum distance to get a sufficiently large viewing angle. This was all about getting more screen real estate, so that’s a big win. If you really want an affordable 31.5″ screen, I’d look for the 2013 Asus PQ321Q that is on Apple’s official list, but that display is MST-only. It has come down from $3500 to a clearance price of about $500. The current Dell 31.5″ 4K (2016 model) also looks very nice, but I’m not sure if this MacBook Pro works with it, and it also is about $1000. I wouldn’t spend that right now when it’s not clear what Apple does about displays and display support in the near-ish future.
The native 1:1 resolution will be too small for many people. You’ll need sharp eyes. I only increased the mouse cursor size and speed a bit and may scale up text size in the browser every now and then. The virtual resolution between 1:1 and Retina “looks like” 3008×1692.
The cheap panel shows when viewed from odd angles. There’s a very narrow sweet spot that you need to sit in to avoid this. The stand helpfully rotates in all directions to help with that. Also pivots to 90°. Factory calibration is not horrible, but way off what the internal Retina screen on the MacBook displays. This will need some more calibration work. The backlight is reasonably even and the matte finish helps with glare, compared to the old 27″ iMac that used to sit in this spot. Also, there are some dead pixels, but they’re small enough not to notice and I probably won’t try to get it exchanged.
The six OSD menu buttons are on the back, with little printed dots on the front indicating where they are. The power button has a little nubbin to differentiate it. This kinda sorta works, but isn’t great. Scrolling through menus, index and middle finger are up and down, and OK maps to the ring finger.
There are built in speakers that do nothing but confirm that the DisplayPort cable also carries stereo audio. There is a 3.5mm audio jack for real speakers though.
I will have to see how this port sounds. Update: Audio from that port is unusable though. No volume control from OS X, and there’s a very pronounced whining noise.
The MacBook Pro is happy to work in clamshell mode, i.e. with its lid closed. It’s summer now, and the fans come on a little more than in standalone mode. If you prefer to leave it open, there’s an NVRAM setting to turn off the internal display when an external one is connected. I’ve come to the conclusion that using only one screen helps me with staying focused, so I really don’t want another screen off to the side.
4K video playback on this i7 is barely possible, and only with fans running at full tilt. VLC has more trouble with the identical files that QuickTime plays without problems. YouTube in Chrome also has problems. But this really isn’t about video but about getting more space to work with, so that’s fine for a Mac from 2013. Remember when Apple used to release better ones every now and then? Ah. Good times.