***neither a teacher nor a native-speaker***
The second suggests that the effort you put in for the search was much more than the first one.
or the second would be used as an answer to such a question:
Q: Do you really want me to believe that you searched ?
A: I did search...What makes it too hard for you to believe?
But a native-speaker will give you more satisfactory reply, so I suggest you to wait for a while.
Student or Learner