As you intuit, 4K def on the same size monitor(s) you had before is of very limited benefit (unless you had really crappy monitors; and Dell Ultrasharps are pretty sweet - there's a reason they turn up in a lot of photo/video editing setups). 4K is simply a way of reducing multiple pieces of hardware into one. A 4K monitor gives you around the equivalent number of pixels of four "regular" monitors. If the 4K is physically too small, you're squinting trying to read it - good luck. If the 4K is large enough, then it's replacing the function of four monitors. The major benefit over 4-up is that you can size your windows to what you want, without a bezel cutting through the middle of your window. Apart from that, the benefit is the same as from going from one monitor, to two, or to three, or to four. You've got more real-estate on which to display information without having to bring a window to the front (which can critically block the primary data you had displayed). You can see in this post, some of the sizing drawings I did for comparison before switching four 28" 1920x1200 for a 55" 4k. https://www.elitetrader.com/et/threads/single-large-monitor-practical.307614/page-4#post-4848393
I use three 46inch TV monitors (not 4k) side by side with the middle monitor (main monitor with my broker trade execution platform) a curved monitor. Yeah, I truly believe traders underestimate the value of their computer/monitor/home office has on their productivity. I tried to explain it once here at Elitetrader.com about the increased productivity and many people here acted like its witchcraft. In fact, I've been using monitors over 40 inch since 2010. Today, prices are cheap enough that most retail traders should be able to afford although the lure is still strong for those that trade from a single screen. Heck, nothing wrong with trying a multiple monitor setup via large screens and if someone doesn't like it...return the monitors because computer companies these days have 30 - 60 day return policies on purchases like that. wrbtrader
I hate to say it after your comment, but there seems to be something almost magical about having a centre monitor. Perhaps as simple as you're facing and looking straight ahead for the majority of your work, and without a bezel in its middle. We're very good at assembling split images, but if you don't have to, less effort less stress. If you're casually looking at it, no big deal; if you're working & concentrating - doing real work - there's a huge difference in speed, accuracy, required effort, and stress. I did the 3-up in landscape, but greatly preferred the 3-up in portrait. Perhaps as there's less physical departure from centre to look to the left or right wings for the additional info. I even did 3-up landscape with another landscape over the centre monitor, but preferred the 3-up portrait. I was paying attention to people-machine interface from the early 80's onward. One thing that became very evident, is how fast and accurate we humans can be, if what we need is presented well and with the least effort for us. I put a lot of testing of my 5/6 populated 2x3 6-up display before going with 4k 55". Horizontal & vertical angles of view, neck movements, text & objects at pixel size and final size, viewing distances, even down to my preferred chair height, all with having a list of what information needed to be presented when, how, logical groupings, its hierarchy of importance. And when something 'goes wrong', what information will be where, do I have to do anything, or am I free to simply look and get the info I need to access, decide and if needed, act. When I first tried the 'Clean Code' parameter newline & indenting, scanning was fast, and accurate. But moving through the code I could actually notice my eyes halt and get drawn back to delimiters, then moving onward. Move, stop, backup, pause, move... repeated. That effort & time matters when you're working with ~80K lines of code. With nothing to lose, I bracketed all delimiters with a blank space, just to see. After that I could just fly through the code. No more getting caught on delimiters. Refactoring was something I'd dreaded the effort of, but at least I'd welcome the benefit. Now it's significantly faster to first reformat a piece of code, then go through it for what it does or where a problem is. And now my eyes aren't tired, I'm not stressed and I'm no longer exhausted after a session of refactoring. Instead of dreading the effort, I look forward to having another piece of code to work on. You have a 6,000 line class, give it here. If someone had tried to tell me that there was something that could make such a difference after all these years, I'd have thought they were nuts.
p.s. I find I tend to use the left half to 2/3 of the 55" 4k as a 'centre monitor' for the most important info. My chair is positioned roughly 1/3 of the way in from the left. Its right side is used like a 'wing' for secondary/supporting info. Tertiary goes on the 28" on the left.
Multiple Virtual Monitors https://elitetrader.com/et/threads/how-to-divide-a-4k-monitor-into-multiple-virtual-monitors.339480/