[neonsunset]

When you say "C# GC's generally resemble the older Java GC's more than G1 or especially the Zgc", what do you have in mind? I'm skimming through G1 description once again and it looks quite similar to .NET's GC implementation. As for Zgc, introducing read barriers is a very strong no in .NET because it introduces additional performance overhead to all the paths that were previously free.

On allocation traffic, I doubt average code in C# allocates less than Go - the latter puts quite a lot of emphasis on plain structs, and because Go has very poor GC throughput, the only way to explain tolerable performance in the common case is that Go still allocates less. Of course this will change now that more teams adopt Go and start classic interface spam and write abstractions that box structs into interfaces to cope with inexpressive and repetition-heavy nature of Go.

Otherwise, both .NET and Java GC implementations are throughput-focused, even the ones that target few-core smaller applications, while Go GC focuses on low to moderate allocation traffic on smaller hosts with consistent performance, and regresses severely when its capacity to reclaim memory in time is exceeded. You can expect from ~4 up to ~16-32x and more (SRV GC scales linearly with cores) difference in maximum allocation throughput between Go and .NET: https://gist.github.com/neon-sunset/c6c35230e75c89a8f6592cac...