* Span<T>: https://learn.microsoft.com/en-us/archive/msdn-magazine/2018...
* C# now has a limited borrow checker-like mechanism to safely handle local references: https://em-tg.github.io/csborrow/
* Here is a series of articles on the topic: https://www.stevejgordon.co.uk/writing-high-performance-csha...
* In general, avoid enterprise style C# (ie., lots of class and design patterns) and features like LINQ which allocate a lot of temporaries.
Also can recommend reading all the performance improvements blog posts by Stephen Toub as well as learning to understand disassembly at a basic level which .NET offers a few convenient tools to get access to.
Helped me a bunch to get Sharpl spinning, much appreciated.
C# is Java-but-with-lessons-learnt, and is significantly less verbose and "enterprisey" in typical usage.
Modern .NET 9 especially embraces compile-time code generation, a "minimal" style, and relatively high performance code compared to Java.
Even if the JVM is faster in benchmarks for hot loops, typical Java code has far more ceremony and overhead compared to typical C# code.
Can you give an example? I don't think this is true anymore for modern Java (Java 21+)
Java currently beats .NET by about 40%: https://www.techempower.com/benchmarks/#hw=ph&test=fortune&s...
I judge more idiomatic / typical code complexity by the length of stack traces in production web app crashes. Enterprise Java apps can produce monstrous traces that are tens of pages long.
ASP.NET Core 9 is a bit worse than ASP.NET Web Forms used to be because of the increased flexibility and async capability, but it's still nowhere near as bad as a typical Java app.
In terms of code length / abstraction nonsense overhead, have a look at the new Minimal APIs for how lightweight code can get in modern C# web apps: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/m...
What matters in practical scenarios is that ASP.NET Core is significantly faster than Spring Boot. If you have a team willing to use ActiveJ or Vert.x, you are just as likely have a team willing to customize their C# implementation to produce numbers just as good at web application tasks and much better at something lower level. There are also issues with TechEmpower that make it highly sensitive to specific HW/Kernel/Libraries combination in ways which alter the rankings significantly. .NET team hosts a farm to do their own TechEmpower runs and it just keeps regressing with each new version of Linux kernel (for all entries), despite CPU% going down and throughput improving in separate more isolated ASP.NET Core evaluations. Mind you, the architecture of ASP.NET Core + Kestrel, in my opinion, leaves some performance on the table, and I think Techempower is a decent demonstration of where you can expect the average framework performance to sit at once you start looking at specific popular options most teams use.
Smaller objects from dropping identity is nice but it really doesn't seem like it gives you more explicit memory layout, lifecycle, c interop etc that C# has with their structs. Maybe I'm missing something.
Then why would they add Span<T>, SIMD types and overhaul ref types in the first place?
If you link an example snippet of the type of code that gave you pause, I’m sure there is a better and more idiomatic way to write it.