U4021QW, MacBook Pro 2018, scaling resolution?

Question

I am a software developer. Considering Dell U4021QW for productivity. I have a Macbook pro 2018 with Intel i9 32 GB + Radeon Pro 555X 4 GB.   Apart from having enough desktop space to open IDE and other windows simultaneously - my main requirement is text clarity and lack of eye strain, which is why 138 ppi native resolution of this monitor is appealing to me. My eyesight is not good enough to run this monitor at native resolution though. So I have to scale this to something like 3840x1620. Anybody has success with this setup and this scaling? If MacBook doesn’t give me good quality scaling, then I don’t see the point of spending money to buy more pixels density. I might as well go with something like Dell U4320Q - even though I prefer the ultra wide aspect ratio of this monitor.

jphughan · Accepted Answer

@robinwood Happy to help. Unfortunately I can't really answer the question as to the net effect of higher DPI with scaling artifacts compared to lower DPI with no scaling artifacts. It may even come down to individual opinions and use cases. But I will reiterate that text is typically where the impact of scaling is the most noticeable, so if your work involves working with code, I would say you're more prone to noticing scaling issues. I know that at least some people who have 27" 4K displays (163 ppi) feel that the density is high enough that scaling artifacts aren't noticeable, but you're not going quite that high. Unfortunately I don't know of any 160+ ppi ultra-wide displays. I guess the issue there is that 160+ ppi desktop displays and ultra-wides are each still a relatively small markets, so the market for those two combined might be smaller than vendors are willing to go after. And that density on a larger display would require a total resolution that's higher than most systems on the market today would even be able to run. Many systems still top out at 4K (or 5120x1440, which is slightly fewer total pixels), but support for resolutions like 5120x2160 and 5120x2880 is still pretty rare, at least outside of Apple's products. And I realize that seeing these types of displays like these in-person is a tough proposition.

I guess what I would say is that if you've got your heart set on a 21:9 display with a lot of pixels and a density upgrade over the norm, you should start with that. If it works out, fantastic. If not, you can return it, and then you've got some alternatives to consider, including options that will at least give you a wider aspect ratio in exchange for accepting lower density. And incidentally, if width is what you're after, a display that is 5120 pixels across and is usable at 100% scaling gives you more workspace than a display that's 5120 pixels across but need scaling to be usable. But if you go with one of those alternatives upfront, then you might never shake that "I wonder if I would've been happier with the U4021QW," thought. So you may as well find out what the U4021QW can do for you, especially if fitting the U4919DW into your workspace might be a bit challenging anyhow. The latter is a full 10 inches wider than the former.

jphughan · Answer

@robinwood macOS had a much earlier, faster, and vastly more successful transition to high pixel density displays than Windows, which still has many applications that don't work properly when scaling to accommodate such displays is used. However, that was achieved by Apple designing only for a single "high pixel density" specification rather than trying to cover an entire range of products as Microsoft did in order to account for the broader PC hardware ecosystem. macOS is designed for two classes of displays, namely standard (100-110 ppi) and Retina (200-220 ppi). The way this works is that application developers who want to support Retina presentation simply have to include so-called "@2x" versions of their graphics, which means a version of that graphic that is 2x wider and 2x taller. If you're using a Retina display, macOS loads that set of graphics assets instead of the regular assets. That was fairly easy for developers to accommodate. And on the user side, it means that if you're using a display within either of the pixel density ranges that macOS is designed around, you'll have a great experience. Otherwise, not so much. macOS does support intermediate pixel densities with "Scaled" modes. But the way those work is by continuing to render at either standard or Retina, and then applying post-render GPU scaling to upsize or downsize the already rendered content appropriately for the desired presentation. As you might expect, that doesn't look as good as rendering natively for the target display's pixel density, but macOS doesn't directly support "@1.5x", for example. (Windows is trying to go this route, and it's largely why it's still struggling now while macOS had this sorted long ago.) And since you mentioned software development and IDEs, the impact of post-render scaling is especially visible on text, since text as a result of being vector-based content can scale infinitely with zero loss in sharpness as long as you scale before rendering -- but if you render first to convert that text into a raster image (set of pixels) and then scale, it won't look as good.

Which brings me to your display. 138 ppi is comfortably above the threshold for standard displays, which you already know since you acknowledge you'll need scaling. But it's nowhere near Retina densities. So you'll end up in this intermediate zone. If you want an ultra-wide display that has a standard pixel density, I would suggest something like a 34" 3440x1440 display, which is a 21:9 ultra-wide version of a 27" 1440p display, or perhaps the "super-ultrawide" 32:9 aspect ratio 49" 5120x1440 display, which is essentially two 27" 1440p displays fused together. Both of those yield a pixel density of 108 ppi, which is still comfortable to use without scaling for most users. Both of those are of course less overall real estate, but if you want wide, then maybe the wider aspect ratio of the latter option will offset the loss of vertical real estate compared to the 5120x2160 display you're looking at. Dell incidentally does make a 5120x1440 display, namely the U4919DW. However, the lower density of course means it will be physically larger, so make sure you can accommodate it. I'd also suggest making sure that your system will work with that display. Dell displays and Macs don't always play nice together, and I don't know how well Macs handle ultra-wide resolutions in the first place. I remember seeing some updates to fix ultra-wide support issues on the new M1-based Mac systems, for example.

robinwood · Answer

@jphughan Thanks for your detailed explanation. That made things much clearer for me. As I was suspecting, Dell U4021QW may not be as good an option as it originally sounded because I can neither use native resolution (everything too small) nor the pixel doubled resolution (everything too big). I will be forced to use something in between which will result in loss of clarity because Mac will be forced to scale AFTER rendering. That is a bummer!

Comparing this monitors to my current setup - 2560x1440 @ 27 inch, 16:9 ... How do you compare the loss of quality due to scaling to a potential gain in quality of having just more pixels to work with? (density of 109 ppi vs 138 ppi). Is the combined effect a net negative in loss of quality? Is it a break even? or I end up with some gain in quality anyway? (Just the clarity aspect)

Again ... thanks very much for your help.

As part of my research I also came across these trio of excellent articles that mirror what you were saying - https://medium.com/elementaryos/hidpi-is-more-important-than-4k-b1b9bb110b43

robinwood · Answer

@jphughan Thanks again! That makes a lot of sense. I too coming to the conclusion that it may just come down to individual use case.

I have considered U4919DW, but I thought that size may be a bit too unwieldy for me. Added to that, I can use a bit more vertical space, especially when I am browsing and editing code.

My second choice is Dell U3821DW which I can run at native resolution just by tweaking with font size a bit at application level for a couple of application that I use most.

I have also played with the idea of getting a LG 27MD5KL-B for a true pixel double resolution on my main monitor and relegate my current monitor (Asus PB278) in a vertical format as an adjunct monitors. Assuming I spend about 90% of time on the main monitor, that may give me both space and resolution. But many people seem to be ditching their multiple monitor setups to ultra wide at this time. It requires fair bit of conviction to move in the opposite direction.

Thanks again much for your help!

Monitors

U4021QW, MacBook Pro 2018, scaling resolution?

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