Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first

Screen Scaling question



  • I am new to raspberry pi 3B+ and retropie in general. I want to know if there are screen size restrictions for playing certain games such as mario kart 64/ds or the legend of zelda. I have a 55 inch flat that I havent't tested it on yet, and i wanted to know how well the games will scale to something of this size. I have googled and googled and googled but have not found any definitive answers.

    As a side question, what are some reasonably larger portable screens that would work? (7" or larger) Would a 15" screen work well?

    Sorry if theres already a question similar and the mods can take this down if this violates a rule.

    Thank you guys so much in advance!



  • Screen size (physical dimensions) and screen resolution (number of pixels) aren't the same thing. Many 55 inch TVs are 1080p, which means they have the same resolution as a 1920x1080 monitor. I have a 10 inch monitor on my Raspberry Pi build that has higher resolution -- more pixels -- than my 65" flatscreen TV.

    Just about all the consoles emulated by Retropie are ones that use far fewer pixels than a modern screen. A Nintendo 64's library mostly runs at 320x240. Generally speaking, running it on a bigger screen just means the image scales. (There are emulators that let you do more than that, but this is a generalization).

    In short -- you will see blocky pixels the larger you make the image. There are shaders and effects you can apply that can change this. Older tube-based CRT screens, which is what most of these consoles and computers used, were naturally a little blurry, and often programmers used this fact to their advantage to get visual effects that are ruined when they are seen on a modern TV and are too crisp.

    You should also be aware that because few monitors today run at such low resolutions, what happens is that the emulator actually renders the low resolution and scales it up. In the case of Retropie, Retroarch then applies even more scaling. There are a variety of settings which can adjust the size and shape of the rendered screen. And then on top of that, you can usually also change the actual resolution of your monitor on which is it displayed.

    These things affect performance. For example if I run Drastic, the DS emulator, I can almost double the framerate by changing the resolution of my screen when the emulator boots. You can do this via the runcommand menu. Similarly, I can triple the performance of the Amiga emulator lr-puae by making sure I am not asking the emulator (which is already pretty intensive for an RPi) to render at too high a resolution.

    In short: games will work fine on big TVs, but will look blocky just because they used less pixels (blocks) when they drew, and the emulator is faithfully recreating that.

    As far as portable screens -- depends on whether you are willing to carry around big batteries or not. You can't power anything over a 5inch, maybe 7inch screen without it needing its own power supply separate from the Pi's.



  • @dontarrestme I don't know what the other emulators use off the top of my head but N64 uses 320x240 resolution by default. If you use the -highres plugins it makes the screen look a lot sharper. I only play my games on my 46 inch TV and it looks fine to me for how large the image is stretched compared to old crt TV's



Contributions to the project are always appreciated, so if you would like to support us with a donation you can do so here.

Hosting provided by Mythic-Beasts. See the Hosting Information page for more information.