When should one prefer 3840x2160 over 1920x1080 for a 15" laptop?

Question

Planning onto getting a 15" laptop and I have two choices, either 1920x1080 or 3840x2160 for the screen.

I have a 4K 32" inch display and the pixels are so ridiculously small that you need a magnifier to see them properly.

I used to have a 15" laptop with 1920x1080 and too, the pixels were ridiculously small.

On both of these environments, of course you have to scale DPI to 150% or more for eye comfort.

Some numbers, from https://www.sven.de/dpi/ :

4K/32": 27.89" × 15.69" = 437.55in² (70.84cm × 39.85cm = 2822.93cm²) at 137.68 PPI, 0.1845mm dot pitch, 18956 PPI²

4K/15": 13.07" × 7.35" = 96.14in² (33.21cm × 18.68cm = 620.27cm²) at 293.72 PPI, 0.0865mm dot pitch, 86272 PPI²

2K/15": 13.07" × 7.35" = 96.14in² (33.21cm × 18.68cm = 620.27cm²) at 146.86 PPI, 0.173mm dot pitch, 21568 PPI²

Question:

Why and when should one consider having 4K resolution on a 15" laptop?

Knowing that:

• I won't do any kind of graphic design, mostly programming, I tend to always scale things up to 125%
• 4 times more pixels to process, i.e. more power hungry, more heat, louder fan noise and pricier as well

Answer 1

Never do 4K on a laptop except if you have a special use case for it. It's indeed more power hungry and more expensive and the pixels are even smaller than the already small pixels of Full-HD

Answer 2

I believe 4k panel on a display that small is overkill.

I'm currently using 13 inch MacBook with 2560x1660 or 32 inch 4k display which look equally great; I believe that 2560x1660 on 15 inch display is a gold spot.

A 4k panel is probably not worth it due to

• excessive power usage
• probably high repair/replace cost due to rareness / complex technology
• the fact that you hardly get any more details, unless you're looking at the screen through an electronic microscope

^{Note that even highest end apple MacBook has got 3456x2234 display, and that's a 16.2 inch one.}

As for processing power, even my 5-years old entry-level MacBook (pre-apple-silicon) doesn't have any problem with running 4k display at 60fps (and it has around 4-5x less graphic processing power than current entry-level MacBook), so I really doubt it would be a problem if that's what concerns you.