WPF element rendering is 20% slower on .NET Core 3.0 than on .NET Framework

[topsterde]

• .NET Core Version: 3.0.0
• Windows version: Windows 10 x64
• Does the bug reproduce also in WPF for .NET Framework 4.8?: No

Problem description:

The attached demo runs on the .NET Framework five seconds and needs 230 MB memory.
The .NET Core 3.0 version is 1 second slower and need 15 MB more memory.

This issue is not related to: #94

Actual behavior:
Slower perfomance and more memory consumption than .NET Framework

Expected behavior:
Better performance and less memory consumption with .NET Core 3.0

Minimal repro:

PerformanceWpfCoreVsFramework.zip

[0xd4d]

Your code includes startup time. Add a button that starts the timer and executes the code each time it's pressed.

Most of the DLLs on .NET Framework are already ngen'd so you won't see much compilation. The .NET Core 3.0 code seems to be crossgen'd but the jitter still compiles lots of code. eg. 445 methods in PresentationCore.dll are compiled vs 10 in .NET Framework.

You can see this yourself if you use PerfView and open Advanced Group -> JITStats.

• net48: 16.9 ms jitting code
• core3: 613.3 ms jitting code (fg 117.6 ms, TC bg 495.7 ms)

[rladuca]

@topsterde @0xd4d We have already filed a bug on CoreCLR for addressing perf concerns between crossgen and ngen.

Can you please upvote, comment, and add your reproduction links to: https://github.com/dotnet/coreclr/issues/26438?

That will help indicate the importance of the issue.

Thanks!