I know I touched upon this in passing in some previous post but I thought I should highlight it again. This past month I learnt that monitors resolutions aren’t the only thing that matters, the pixel density too hugely matters.
I had two monitors – both full HD 1920×1080. They worked perfectly fine under Windows 10 and I never noticed any issues with them. They weren’t expensive monitors either – just two (an LG and a Samsung) monitors I happened to find at a relatively cheap cost, the only criteria being that they support full HD as that resolution was important to me.
Fast forward to this past month when I purchased the Mac Mini and got this Plugable Thunderbolt Dual HDMI adapter and decided to hook these two up with the Mac Mini. Boy was it a torture working with these monitors after that! The LG one was better than the Samsung but both had such fuzzy text and it just cringed my eyes even looking at that. I Googled about this and found some forum posts that suggested changing the HDMI cable, so I did that but it didn’t improve things by much (maybe a bit, but that’s probably a placebo effect). That’s when I learnt about Pixels Per Inch (ppi) and what Apple means by Retina monitors.
So – pixels per inch is the pixel density of the monitor. My LG monitor was a 21.5” 22MP58VQ which had a ppi of 102. The Samsung was a 23.5” with a ppi of 93 (yeah, worse than the LG, coz it was larger and so the pixel density is lower). Thing is both of these numbers are low, and I am not sure what is about the macOS but my eyes were able to discern the low ppi on both these monitors. The only way to fix this is to get a monitor with a larger ppi, but unfortunately you don’t get much high ppi monitors in the full HD resolution range. If you want better ppi you must go 4k. A quick Googling on affordable 4k monitors with good ppi (based on opinions from macOS users) pointed me to the 23.8” LG 24UD58 monitor, which has a ppi of 185.
For any one else interested, this DisplaySpecifications site is a good place to input your monitor model and find its ppi. Useful when considering what monitor to purchase. Also, I came across a blog post by Casey Liss (whose podcasts I listen to, e.g. ATP with Marco Arment) and he too recommends the LG 24UD58 as a good budget option, along with some more pricier options.
Apart from a monitor with high ppi, it is also important to get one that supports HDMI 2 (and not just the monitor, but any adapters too that you use – such as the Plugable one I was using – and also proper cables etc). Only HDMI 2 can run a 4k display at 50 or 60 frames per second so if you are stuck with HDMI 1 then it is better to use DisplayPort. 50 or 60 fps wouldn’t have mattered in my use case (I don’t game) but it is better to be aware and get something that supports it to future proof your investment.
Once I had all this in place I was able to drive two 4k monitors easily from my Mac Mini. Later on I ditched the Mac Mini and went back to the MacBook Pro as my primary computer (as it fit better with my workflow, while the Mac Mini was better suited to certain other tasks I had in mind) and thus I have finally have decent external monitor output when using macOS. Yay!