Mikelav69,   There isn't anything other than I would recommend that prior to installing the M640 you update the CMC, as well I would also update the M640s BIOS, iDrac, and controller once installed.    Hope this helps.  
Hi, I'm looking at upgrading a M1000e chassis with M640 blades. Does anyone have any good documentation on the upgrade process and order.....and any gotchas and/or potential issues We also use openmanage so I assume this should get upgraded first? thanks
Upgrade advice - M1000e and M640 blades