Laptop showing resolution beyond its normal maximum, when plugged into a screen

It is because it is doing screen mirroring and assuming that the external display is your "primary" display. As a result it is rendering at the maximum "native" resolution and then scaling it down for your built in display.

The alternative would be setting it to your internal display resolution (1366x768) and scaling it up to the external display resolution of 1920x1080. This will result in the external display being blocky and looking bad

If you want two independent displays rather than one single mirrored display you will then have the option of using each display at its native resolution. I.e. 1366x768 for the internal display and 1920x1080 for the external.

You can cycle through the various options of internal and external displays by pressing Windows+P. The options you have are

internal display only
duplicate - what you are seeing
extend - two fully independent displays, able to move programs between them
external only

Mokubai

Posted 2017-12-22T09:19:45.833

Reputation: 64 434

Yeah, I'm aware of the different features of connecting to an external display. Thank you for the help, this answered what I need to know. And I guess it is better than scaling it upwards :-P.

I'll probably extend the displays, it's more efficient for me anyway. Thank you! – Alex M. – 2017-12-22T10:23:12.370

11It's not that it thinks the external should be the primary (the same happens if the laptop resolution is higher than the external, but the other way round.) Instead, the assumption is that it is desirable that the highest possible resolution be set. As the display is duplicated, both displays need to be displaying the same (base) resolution image. The scaling occurs because of problems with old systems that would limit the availiable resolutions to the set supported by both devices. Different aspect ratios led to very low resolutions being used by default. – Baldrickk – 2017-12-22T10:47:06.753

1Some laptops also offer an fn + f<number> key combination to switch between these presentation modes. But don't try each combination. You might end up locking your touchpad without knowing how to unlock again. For this, it's best to check the manual (if it has one). – Ismael Miguel – 2017-12-23T10:01:25.430

1@IsmaelMiguel : Or, better yet, try each of the keys (there is probably only one) that has the right symbol on the key, or printed just "above" the key (further away from the space bar). The right symbol is a couple of squares that overlap, one higher and to the side of the other. (Or, sometimes the symbol is slightly, with a couple more lines representing monitor stands that the squares may sit on (even though the laptop's display would be standless) – TOOGAM – 2017-12-23T18:20:43.520

1@TOOGAM Actually, the symbol varies a lot, and even the functionalities vary a lot. But that's a good starting point. – Ismael Miguel – 2017-12-23T18:36:40.340

1It is operating system specific. You should tell about your OS – Basile Starynkevitch – 2017-12-22T17:49:52.750

Is it just blurry on your laptop screen, or is it blurry on the external screen too? – CJ Dennis – 2017-12-23T02:11:30.590

CJ Dennis, it's just blurry on my laptop screen. Is it to do with this?

– Alex M. – 2017-12-23T08:52:59.097

Laptop showing resolution beyond its normal maximum, when plugged into a screen

Answers