Discussion: WinUI Performance comparison between C# & C++

Comparing the performance in WinUI to create component

Discussion: WinUI Performance comparison between C# & C++

While comparing the simple “for loop” between C# and C++ there is vast difference in performance.

For Eg:

WinUI C# for loop

List<string> stringCollection = new List<string>(); for (int i = 0; i < 100000; i++) { stringCollection.Add("item"); }

or foreach loop

foreach (var item in stringCollection) { } took 0.002 sec

but in WinUI C++

IVector<hstring> stringCollection= winrt::single_threaded_vector<hstring>(); for (int i = 0; i < 100000; i++) { stringCollection.Append(L"item"); }

or for (auto item : stringCollection) { }

took 0.2395 sec (IVector or IObservableVector have same performance.)

It looks C++ performance is low compared to C#. So, which one will be good choice for creating component in WinUI based on performance and memory consumption.

Related Links

https://docs.microsoft.com/en-us/windows/uwp/cpp-and-winrt-apis/collections

[kennykerr]

As @sylveon pointed out, this is not a meaningful comparison. And as @riverar notes, this has nothing to do with WinUI. If you gave both C# and C++ a WinRT IVector<hstring> you will find that the C++ version outperforms the C# version by a very considerable margin. I wrote about this a few years back.

But here you’re comparing a native C# list with a COM interface. The C# version will obviously outperform the C++ example because the C# version is inlined whereas the COM interface can never be inlined (no matter the language). A better comparison would be a C# List and C++ std::vector.

If you are looking for the best possible performance for COM/WinRT/WinUI, C++ outperforms C# every time.

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