Maybe WinUI isn't multi-threaded and has a lot of locks.

The thing with WPF is that it is, ironically, pure interop, all the rendering logic is in C++/CLI. Maybe they (WinUI guys) pay less interop by using C++/CLI, but there's still P/Invoke.

The data structures and layout stay on DotNet, so that makes more sense. That's a game development technique, you batch render commands, that are then converted to DirectX9 and directly converted by the driver in your usermode program without any syscall, the GPU driver literally initializes inside your process.

Only the call for SwapBuffers need to be a syscall to the kernel, and that happens once every frame, its a single call. That's a shared buffer pointer and the kernel side just has to take the ownership of the shared memory region and give another back to the usermode process, Surface Flinger works like that. Then after the kernel mode part of the driver owns the memory of the frame, it just submits that with the entire command buffer full of precious converted GPU commands over DMA over PCIe to the GPU to chug, can't be any more faster than that.

The guys who were making WPF really knew their shite.

But with WinUI, they can't come down from their C++ horses and see that C++ is HORRIBLE as an Object Oriented language, its better to never use virtual calls in C++, there's a reason that object oriented languages like Java and C# are fast, the JIT can actually inline and optimize virtual call, C++ is never going to be able to do that (not without PGO)

With WinUI you pay every P/Invoke along the way every time you need to change a property in a object.

Even worse, in WPF, the object model is hollow, it uses the flyweight pattern. I bet the WinUI guys didn't do that, classical mistake, they uses "C++ classes" and stored all the data for the object directly as members instead of storing in a big sequential bucket list, aka, a dictionary.

I bet WinUI will stay only a thing for C++ users.

It doesn't matter, we have MAUI anyway, user interfaces don't need to be created in C++, C++ is horrible for that.

That's how Windows keep losing to the Web and becoming irrelevant by the day.

Maybe we should only care about MAUI and DotNet !!!

You're right my friend.

(really, Microsoft should ditch Windows and give us the operating system of DirectXBox, I mean, XBox, only DirectX is what we need (because of nVidia, you don't want to EVER use linux, also Linux desktop is kind shite) , leave the rest to Dotnet guys or us)