Hello guys! I'm planning on upgrading my stock 2009 Mac Pro 2.26GHz processors to the 3.33 GHz W5590's and I'm just doing a lot of research first. I read a few threads on here of successful upgrades but I just have a few questions about things that weren't clear before I start ordering. 1. What is the 2mm thermal padding for? 2. Do I HAVE to add the 2mm thermal padding and what kind exactly? 3. Is it best to use washers for the lid spacing instead of guessing how tight to make the screws? 4. Do I have to upgrade to firmware 5,1 for these processors to work? I am using 1066MHz ram (not 1333). This computer is used for audio recording in case anyone is wondering. Thanks in advance guys!