performance criteria on DEFINE()

Hi, We have a big multilanguage project. For a while we used gettext to translate the pages, but we gave up on this because of many problems. Out solution is to create a file for each language which includes the "label" definitions. for ex: define("LABEL1", "label 1"); define("LABEL2", "label 2"); etc... Now, one of this file can contain more than 2000 defines and we make a calculation that we will reach 8000 in 2 years. I made some testing(generated many label) in including these files into the project it seemed to work fine. I don't know how php handles these defines(memory usage, CPU etc) so the question is: how much affects the performace the inclusion of a lot of defines??? Andy.