That&#x27;s really hard to claim. Both are languages, and don&#x27;t have inherent performance characteristics, C# can even be compiled to native for some targets.<p>There are some aspects of C# (such as value types) that can give an advantage of <i>idiomatic C#</i> over <i>idiomatic Java</i>, but for anything performance sensitive you aren&#x27;t going to write idiomatic code anyway, you&#x27;ll be writing pretty convoluted code with SoA instead of AoS and so on.<p>As for the respective VM:s, the CLR vs the JVM, the performance differences are pretty small. You wouldn&#x27;t rewrite from Java to C# for performance.