c# - OrderBy().Last() or OrderByDescending().First() performance

Question

I know that this probably is micro-optimization, but still I wonder if there is any difference in using

var lastObject = myList.OrderBy(item => item.Created).Last();

or

var lastObject = myList.OrderByDescending(item => item.Created).First();

I am looking for answers for Linq to objects and Linq to Entities.

Answer 1

Assuming that both ways of sorting take equal time (and that's a big 'if'), then the first method would have the extra cost of doing a .Last(), potentially requiring a full enumeration.

And that argument probably holds even stronger for an SQL oriented LINQ.