May 14, 2021

On the iMac 24in M1

The iMac 24in is my perfect monitor — if I squint a little. If you add the M1 computer hidden in its chin, you get my perfect computer… only not so much perfect than my current configuration.

iMac vs DelliMac vs Dell

Last summer when I bought my beloved Dell PC2421DC 24in 1 monitor I accepted its non-retina QHD (2560x1440) resolution because the smaller screen size was less bad than other options. I seriously considered a few 4K monitors, but because of price and didn’t want to deal with scaling and performance hit2.

The new iMac M1 24in sent me down a what if? rabbit hole. If switched this MacBook Ait M1 + Dell 24in QHD come for a new iMac — how would my display situation look?

Monitor Size

Monitor height x width x length (in)
Dell PC2421DC 14.02 x 21.17 x 1.68
iMac 24in 18.1 x 21.5 x 0.45

Mind you, the iMac chin is the computer, which requires we compare…

Viewing Area

Monitor Diagonal (in) Display Area (in)
Dell PC2421DC 23.8 20.75 x 11.67
iMac 24in 23.5 20.48 x 11.52 3

Here we see the panels are very close in size, so we can move on to the really important part:

Native Resolution

Monitor Native Equivalent
Dell PC2421DC 2560 x 1440 2560 x 1440
iMac 24in 4480 x 2520 2240 x 1260

So close! but, regardless of the quality of the display resolution (PPI) we’re sacrificing area. Unless…

Resolution Scaling

Monitor @100% @150%
iMac 24in 2240 x 1260 2520 x 1417.5
iMac 21.5in 2048 x 1152 2304 x 1296

With a little of the scaling I was so allergic before, we arrive at a a close to QHD equivalent resolution with better PPI. In my defense, it’s not quite the same because a 4.5K monitor has more pixels than a 4K monitor. Which means that the UI sizing is going to scale consistently, not having some assets in hi-DPI while others in standard resolutions.

Still, I’m going to wait for the Pro version of the iMac — mostly because of the Display. A 27in 5K iMac would have driving me mad with configuration anxiety on Apple’s website. Luckily, I’m currently my best Mac setup ever — which allows to be a bit responsible.


  1. More here My 2020 Software and Hardware of the Year↩︎

  2. My early 2020 Intel MacBook Air had enough difficulties driving its own display.↩︎

  3. Estimated. I couldn’t find any measurements on Apple’s site, but using the Diagonal Measurement, the screen resolution and good old pythagoras, you can get an estimate.↩︎