I think reading how much RAM a program uses is a bit complicated. In example there are shared libraries, and RAM will be reused if multiple applications uses the same resource. If two programs using the same library uses up 1.2gb on their own, then starting up app A and measure its 1.2gb, then close and measure app B with 1.2gb would give you exactly that. But in reality if both apps would run at the same time, their total RAM usage might be just 1.4gb.

As an example, if I already run KDE on my system and another KDE app starts up, it might not use too much more RAM. But the same app on a GNOME system might require a lot of additional RAM. So the Windows 11 Weather app might not even use 1.2gb on its own. No idea how they measured it.

Summary

• Windows 11 Weather app hogs about 1.2GB RAM and spawns multiple Chromium processes.
• App displays ads because it wraps MSN weather in a WebView2/browser shell.
• Native macOS Weather uses ~247MB with no ads; Microsoft should port to WinUI 3.

While shared memory is a feature in linux, it's mostly used for inter-process communication and isn't something that happens by default with shared libraries.

When a program loads a shared library, it creates a new instance of it that runs in the same memory space as the program.

In the example you're using with KDE, that's actually a system process that your program is communicating with, so it's not quite the same as just loading a shared library (.so).
Since new programs can connect to the existing system service, that can end up saving RAM by having a single system program service multiple user applications.

This isn't really any different on Windows where the desktop environment (dwm.exe) is handling drawings and compositing for all user apps.

Edit: Based on the downvotes, maybe I got something wrong here. Maybe someone can comment on what? I'm happy to learn

Even 247MB seems too much for usually checking the weather. Once upon a time, the entire operating system was able to run without any problems on less than 512MB of RAM, including programs, and now you tell me that I need half of it to check the weather? Technology has lost itself along the way...

I had to look it up. Yuck. A lot of users are just beta testers aren't they? At least with Linux you know that people care about fixing it. But Windows, it's a mess.

While shared memory is a feature in linux, it's mostly used for inter-process communication and isn't something that happens by default with shared libraries.

When a program loads a shared library, it creates a new instance of it that runs in the same memory space as the program.

In the example you're using with KDE, that's actually a system process that your program is communicating with, so it's not quite the same as just loading a shared library (.so).
Since new programs can connect to the existing system service, that can end up saving RAM by having a single system program service multiple user applications.

This isn't really any different on Windows where the desktop environment (dwm.exe) is handling drawings and compositing for all user apps.

Edit: Based on the downvotes, maybe I got something wrong here. Maybe someone can comment on what? I'm happy to learn

Even 247MB seems too much for usually checking the weather. Once upon a time, the entire operating system was able to run without any problems on less than 512MB of RAM, including programs, and now you tell me that I need half of it to check the weather? Technology has lost itself along the way...

Almost 300mb to show the weather? Apple should be ashamed.

You're not that far off, everything you've said about shared memory is true of writable shared memory, which is what is usually meant when talking about "shared memory" in user space.

When a program loads a .so a version of that file is loaded in the program's virtual memory space so technically that same .so file exists in multiple virtual spaces, but that's only a trick used by your MMU (memory management unit), the .so file is only loaded once in actual memory:

Let's imagine some program loads opencl.so and no one else on the system uses it. The kernel will check all needed libs and loads that one at physical address 0x700. After loading it up it talks to the MMU and creates a virtual address space for said program, telling the hardware to create a read-only link between virtual address 0x100 and physical address 0x700, "loading" the library in virtual memory (without actually making a copy). If some other program then needs opencl.so the kernel will recognize that lib as already loaded so skips ahead to linking virtual adress 0x200 (or whatever really, virtual address space is specific to one instance of one program, it could be 0x100 again it doesn't matter) to physical address 0x700, once again loading it in program memory without making a copy.

Ads In a weather app, because of course

Summary

• Windows 11 Weather app hogs about 1.2GB RAM and spawns multiple Chromium processes.
• App displays ads because it wraps MSN weather in a WebView2/browser shell.
• Native macOS Weather uses ~247MB with no ads; Microsoft should port to WinUI 3.

Imagine paying for an OS and then get served ads. That shit should be illegal.

@Muffi @thingsiplay
When I was a child and didn't know about the two money problem, I felt the same way about pay TV (cable). Why should we pay for it with dollars and also with ads?

300mb is what apps on Android used to take up back when 4GB RAM was standard. Macs have shipped with 8GB on base model for many years. This is not an issue, sorry

Summary

• Windows 11 Weather app hogs about 1.2GB RAM and spawns multiple Chromium processes.
• App displays ads because it wraps MSN weather in a WebView2/browser shell.
• Native macOS Weather uses ~247MB with no ads; Microsoft should port to WinUI 3.

Edit: There was no need to delete your reply. I just explained it without any toxicity. Context for any reader: He was saying that as a kid they had to pay for cable tv and still got ads on the tv programs. As a justification for why Windows has ads.

Because you pay for access on your cable provider, like you would pay for your internet on your internet provider. Then you can watch free channels or pay for certain channels, like you would pay for Netflix or Disney+ or whatever is called. With the paid services there shouldn't be any ad, with the free services like YouTube, you get ads so YouTube can pay their bills.

So, you analogy was completely missing the point and is not comparable to a paid operating system. You don't even get ads with free operating systems, or with your paid competitor Apple.

Relative size it’s ok. Absolute it’s still way too much for what the app is doing.

Have you used the app in question? There’s animated hi res backgrounds that have to be loaded for diff locations, a live map, tons of detailed widgets and animations… 300MB seems reasonable to me. You might not want any of these things on a weather app, hence there are many to choose from out there

Summary

• Windows 11 Weather app hogs about 1.2GB RAM and spawns multiple Chromium processes.
• App displays ads because it wraps MSN weather in a WebView2/browser shell.
• Native macOS Weather uses ~247MB with no ads; Microsoft should port to WinUI 3.

Even 247MB seems too much for usually checking the weather. Once upon a time, the entire operating system was able to run without any problems on less than 512MB of RAM, including programs, and now you tell me that I need half of it to check the weather? Technology has lost itself along the way...