If you are after a 4K / Ultra HD display this holiday season, the Dell P2415Q is a great monitor that can be found for just over $400 USD while not running into any compatibility troubles under Linux.
Just over one month ago I purchased the Dell P2415Q as the latest 4K (3840 x 2160) display at Phoronix for all of our graphics testing and for newer 4K tech than other displays here like the Seiki 4K display of a few years ago or this low-cost Acer 4K display that's limited to 30Hz @ 4K. Over using it daily the past month, I'm quite happy with this monitor so just wanted to pass along my praise and recommendation of it as an affordable 24-inch 4K monitor.
The P2415Q has inputs for DisplayPort, Mini DisplayPort, and MHL HDMI. There's also a DisplayPort output too. Additionally, there's a speaker-line out and built-in four-port USB hub. This monitor supports 60Hz @ 4K. The monitor is rated for 178 degree viewing angles, 1.07 billion colors, 300 cd/m2 brightness, 1000:1 contrast ratio, 6ms GTG, and has a maximum power consumption of 90W with a typical power use of 45W. The panel type for this lower-end 4K display is AH-IPS.
Over the past month I've tried out the display with all combinations of the major open and closed-source Linux graphics drivers. None of the displays have run into any issues with faulty EDID or other problems when trying both the DisplayPort and HDMI connections for 4K operation. The only word of caution I have to pass along at this time would be the need to use Linux 4.3+ with Intel graphics for proper 4K support. I also encountered no dead pixels or other issues.
With a current price of $409 USD, the Dell P2415Q is the best 4K display I've found for the price in my research I did back in October. So far I'm extremely pleased with the monitor and would recommend it for Linux desktop users looking to jump to 3840 x 2160 computing.
I found the best pricing for this Dell 4K 24-inch display over at Amazon.com where you can also find more information on this product.