I don't code in C# but it would be interesting to surround the code in just a block instead of a try-catch block and see if the same behavior is evident. If a p

I don't code in C# but it would be interesting to surround the code in just a block instead of a try-catch block and see if the same behavior is evident. If a plain block is still slow, then maybe branch prediction gets overwhelmed with considering having to unwind the stack all the way to main and dealing with open streams and objects on the stack. edit: I don't know byte code or machine code well so my description of what happens unwinding the stack is probably wrong, but my point is just that it's simpler for the CPU not having the possibility of unwinding the stack beyond the code section OP called out.