>As I was told, all the software and settings on the new server is exactly the same as on old one (cannot check that myself).

That's an incredibly bold statement, considering the number of "software and settings" there are on an NT server (any version)

Besides, didn't you know that NT slows down as version numbers increase? this is called "progress" If the new version worked better on the same server as the old version, you'd have no reason to buy (expensive) next generation hardware.