AD Queried Take Too Long

[Brad King]

I have been working for sometime with limited success on a web service to
return all users from AD. Limited queries and single queries are returned
instantly, But, whenever I attempt to return all users this can take upwards
of 2 mins and sometimes even longer. I have scripts in PHP that are building
the same type of array that take only a few seconds.

Any Ideas ?

---CODE--
public ArrayList QueryAllinADSI()
{
ArrayList TestArray = new ArrayList();
DirectorySearcher ds = new
DirectorySearcher("(&(objectclass=organizationalPe rson)(physicalDeliveryOfficeName=*))");
SearchResultCollection results = ds.FindAll();

foreach(SearchResult employee in results)
{
try
{
DirectoryEntry employeeEntry = employee.GetDirectoryEntry();
string strReturnVal =
employeeEntry.Properties["displayname"].Value.ToString();
TestArray.Add(strReturnVal);
}
catch (Exception ex)
{
TestArray.Add("Error: " + ex.Message);
}
}

return TestArray;
}