Must-read articles on string comparison performance

I've always wondered which is the fastest technique to do a string comparison? using the StringComparison enums or ToUpper and ToLower? The following entry also answers what is fastest among the StringComparison enums.

https://blogs.msdn.com/b/noahc/archive/2007/06/29/string-equals-performance-comparison.aspx

This article has more detail on do's and don'ts for stringcomparisons:

https://msdn.microsoft.com/en-us/library/ms973919.aspx