Hmm interesting, some are saying keep the paste that came with arctic freezer 64 pro and others agree that i should use the AS5. However, is the process of removing the existing MX-1? paste from the 64Pro and applying AS5 really worth it? AS5 costs around £5 and also a cleaning fluid will be needed to clean the surface in the first place (£2 from chemist for some Isopropyl alcohol).