RGB, BGR, v-RGB, v-BGR, oh my!

[Jaxidian]

So I'd like to make sure I understand this properly. I know I understand sub-pixel arrangements of RGB vs BGR. The following image makes a whole lot of sense to me where the text anti-aliasing is crap because it's configured for RGB but the subpixel arrangement is actually BGR. In this image, you can see that the anti-aliasing is actually backwards on a per-pixel basis. In other words, as the A slants up, you can see "jaggies" sticking out, and likewise when it's slanting down. If these pixels were RGB and not BGR, then those "jaggies" would be flipped which would mean that they'd be along the letter providing for the smoothing effect that anti-aliasing is meant to provide. So this all makes sense to me.

And a neat side-effect of this understanding is that if you take a BGR monitor and mount it upside down and flip the orientation by 180 degrees in Windows (or presumably also on a Mac), you have effectively turned your monitor into one with an RGB subpixel arrangement. Neat!

But here's my question: What happens when I rotate my monitor by +/- 90 degrees? How does Windows and MacOS handle this? Are they smart enough to know that instead of having subpixels that are side-by-side that instead they're now stacked on top of one another? Or does this just result in botched anti-aliasing that is going to strain my eyes whether I realize it or not? There's some info on this site but it appears to be dated and I simply don't know if anybody has a solid answer to this on Windows 10 (what I'm specifically interested in since that's what I use).

Would love if somebody much smarter than I am could chime in on this! :-)

[iBurger]

But here's my question: What happens when I rotate my monitor by +/- 90 degrees? How does Windows and MacOS handle this? Are they smart enough to know that instead of having subpixels that are side-by-side that instead they're now stacked on top of one another? Or does this just result in botched anti-aliasing that is going to strain my eyes whether I realize it or not? There's some info on this site but it appears to be dated and I simply don't know if anybody has a solid answer to this on Windows 10 (what I'm specifically interested in since that's what I use).

From experience I can tell that font-smoothing is turned off when you rotate an external display with 90 degrees on the Mac. It becomes quite obvious that the font-smoothing is turned off because everything looks less nice. (more sharp, more edgy). Windows 10 supports BGR out-of-the-box so you should have no problems. (not sure about 90 degrees though, my guess is it won't work then).

Finally, it should be said that with higher DPI numbers font-smoothing becomes less important. For instance, Apple has no font smoothing on the iPhone. This makes sense because you are constantly rotating the screen, if you hold it differently of course. Ever since the iPhone 4, Apple has put retina screen in the phone and these screens have a really high PPI count (165).

If you are like me, and you want to buy a 43 inch 4K screen, like the U430, font smoothing matters again since the DPI is quite low at 110 PPI. However, if you are going to buy a 32 inch 4K screen, I'd forget about font smoothing. The screen probably will look nice without font-smoothing turned on. It all depends on the screen size you are getting.

https://www.sven.de/dpi/