Unit test execution speed (how many tests per second?)

Question

What kind of execution rate do you aim for with your unit tests (# test per second)? How long is too long for an individual unit test?

I\'d be interested in knowing if

Answer 1

I judge my unit tests on a per test basis, not by by # of tests per second. The rate I aim for is 500ms or less. If it is above that, I will look into the test to find out why it is taking so long.

When I think a test is to slow, it usually means that it is doing too much. Therefore, just refactoring the test by splitting it up into more tests usually does the trick. The other times that I have noticed my tests running slow is when the test shows a bottleneck in my code, then a refactoring of the code is in order.