I had been limping along with a 5 year old NEC 3090 as it started to fail over the past few months, but didn't want to replace it with another low DPI screen when I knew the 4k stuff was coming right around the corner. Then a few weeks ago Dell announced a 24" UltraHD (3840 x 2160 pixels) display in their UltraSharp PremierColor series, the so-called 2414Q. I watched and waited for it to be available on Dell.com. Every morning waiting for the button to go from "Contact Dell" to "Buy Now" and it finally did a couple of weeks ago. After some delays in shipment my screen finally arrived this morning and I thought I'd write a little post on my experiences. This will be updated as I fiddle some more, so be patient.
First Encounter I plugged the screen into my very fast i7 Ivy Bridge Hackintosh with a GTX 760 GPU and I got full resolution on the first try. The problem is that it's stuck at 30Hz refresh rate. Now the GPU has Displayport 1.2 and in Windows 8.1 people have been running similar screens at 60Hz. Apparently the Nvidia driver built into Mavericks (there is no Nvidia web driver for Mavericks yet, or ever) does not support what's called MST or Multi-Stream Transport. Basically the way screens these hi-res screens work is that you send two screens worth of data (that's the Multi-Stream part) over the same cable and the screen just displays them next to each other on the same panel. No MST in the driver means I'm stuck at 30Hz. I've heard that the latest Nvidia Web Drivers for Mountain Lion has MST support, so I'm currently cloning my last 10.8 installation over onto an extra drive to see if I can get it working over there. Sometimes when you're on the bleeding edge, you get cut.
The other issue I'm having is that the built-in resolution scaling is not working. So my screen is actually running at the full 3840x2160, which on a 24" monitor is pretty tiny. Not completely unusable for messing about testing, but not the kind of thing you'd want to stare at all day long. So once I get the refresh rate problem nicked, I'll figure out how to get it to show screen real estate something closer to 2560x1440 only with a whole lot more pixels to smooth things out.
That said, my initial playing around with images in Lightroom has made me feel similar to how I felt when I first upgraded to a color calibrated screen. All the little flaws in sharpness that you really didn't notice before because you were going between a low-res overview and 100% are now glaringly obvious, much like they are when you look at a print. It's pretty amazing. 180ppi on a desktop screen. Yum.
Round Two My next move was to install 10.8.5 on an extra drive to see if the passing comment I read on an online forum was true. The idea was that the web drivers that Nvidia themselves released for Mountain Lion allowed for the illusive MST mode. No dice. Unfortunately I had the same results as in Mavericks. Looks like I may have to want for a driver update or some coding genius to come along and help me out.
HiDPI Mode (Kinda!) Ok, so I've made some progress. I've got the screen running like a pixel doubled 1080p screen. So it's showing the screen real estate of 1920x1080 while being really really smooth and sharp. To do this I had to enable HiDPI mode in Mavericks using this terminal command:
sudo defaults write /Library/Preferences/com.apple.windowserver.plist DisplayResolutionEnabled -bool true
Once I did that, 1920x1080 (HiDPI) showed up under the 'Scaled' section in the display preferences. The problem was that every time I tried enable it, the system would automatically select a refresh rate of 30.3Hz which made the Dell monitor just barf and show me a black screen. To get past this hurdle I switched back to 'Best for Display' and then selected 'Scaled' again while holding down the Option key. That allowed me to choose 30Hz AND 1920x1080 (HiDPI), and Voila! Retina style beauty. The next step is for it to give me a little bit more room to breathe. What I'd love is the real estate of 2560x1440 while using the pixels to smooth things out.
I still have the problem of 30Hz vs 60Hz refresh rate, but that may have to wait for a driver update that may or may not come. That said, we're back in the "Ok, I'm going to keep this thing" camp. I don't think it's going back. Also apparently there is a bug in Chrome that makes it completely slow on HiDPI external monitors. So I'm temporarily using Safari for the time being.
More to come as I continue my troubleshooting...