@notplants The lcd segmented displays on the old Nintendo Game & Watch have crisp edges 🤷
To actually respond to your question though, the metric you are looking for is "pixel density", similar to "DPI" (dots per inch) from the world of printing.
Celly Phones have really high pixel density screens. You could probably just peek at your friends' phones and see how they look to you, and then look up the model of phone online and see what its pixel density is, then compare that to laptop screens.
Apple is the main hardware vendor for super high pixel density screens on laptops. There are also some other laptops that feature 4k screens, but in general those are the kind of products that I would personally try to avoid as much as possible -- expensive blinged-out and consumer-oriented products that sacrifice functionality for impressive sounding specs.
Cuz here's the thing. The number of pixels goes up as the square of the pixel dimensions of the screen. So the finer the edges of the text get, the exponentially more power the machine will consume, the more complex the software to display things on the screen will have to be, etc.
I think apple actually renders a lot of non-text things at 1/2 scale to give the machines decent performance. When I play video games, even on my 1680x1050 display, I turn down the rendering resolution to make the game smoother. When I'm working with video, especially capturing video, again, I turn down the resolution a lot so that people who I am presenting the video to can actually see WTF I'm doing.
Personally I don't think all the problems that come with using a high resolution display are worth it. If you really just want a 4k display on a laptop tho, I'm sure there are some products out there you could buy, even used ones these days.
@forestjohnson @notplants thanks for this detailed explanation @forestjohnson , I appreciate it, and learned a bunch from reading it.
will have to sit more with whether I actually care about the blurred letters or not, and in general feel you on the weird trade-offs one might have to make to support higher resolution
although on the other hand my macbook of ten years of age really did work well for ten years. also wondering about running linux on old macbooks now, just for the screen… hmmm let’s see
@notplants Ah sorry I didn't understand what you were asking at first.
AFAIK that lspci output doesn't positively identify the GPU you have, but from this PDF it sounds like it should be intel HD graphics 4000?
https://psref.lenovo.com/syspool/Sys/PDF/withdrawnbook/ThinkPad_X230.pdf
And StackOverflow says the max res for that GPU would be 2560×1600 through DisplayPort
https://superuser.com/questions/1317793/does-a-thinkpad-x230-i7-support-a-4k-external-monitor
In general, as a very old laptop, it probably wouldn't be very usable with a high density screen even if the GPU did support it.