This does not seem to be a good way to fix tests:
Also when writing Performance tests - make sure to time the right thing. For example measuring log.Write may give very varying time durations, measure as little block as possible, so instead of:
...
DateTime startTime = DateTime.Now;
regularGridCoverage.Resize(10000, 10000, 1, 1);
log.DebugFormat("Writing 100000000 values took {0} ms", (DateTime.Now - startTime).TotalMilliseconds);
Assert.Less((DateTime.Now - startTime).TotalMilliseconds, 25000);
...
Write:
...
var startTime = DateTime.Now;
regularGridCoverage.Resize(10000, 10000, 1, 1);
var duration = (DateTime.Now - startTime).TotalMilliseconds;
log.DebugFormat("Writing 100000000 values took {0} ms", duration);
Assert.Less(duration, 25000);
...
Or:
...
var stopwatch = new Stopwatch();
stopwatch.Start();
regularGridCoverage.Resize(10000, 10000, 1, 1);
stopwatch.Stop();
log.DebugFormat("Writing 100000000 values took {0} ms", stopwatch.Elapsed.TotalMilliseconds);
Assert.Less(stopwatch.Elapsed.TotalMilliseconds, 25000);
...
Also make sure that message is written showing how log it took to do something, otherwise it is hard to check how long it takes on build server.