Performance of HtmlHelper vs Razor Helper (@helper)

Question

I understand that there are different ways to render reusable HTML snippets in ASP.NET MVC. Here are two possibilities that people generally refer as a "helper" approach:

1. HtmlHelper Extension Methods
2. Razor Helper Methods (e.g. @helper functionName() { } )

Which performs faster?

NOTE: I already know that the performance of an HtmlHelper is faster than a Partial View. But, my question is about comparing the performance of HtmlHelper -vs- Razor Helper (e.g. @helper syntax)