To help with memory load i usually do two things , I shut off the Millenaire and Matmos (add the ambient sounds) Mods and it make a 30fps difference in my game play.
To shut off individual Mods go into your Config folder and open modloader.ini in a text editor and just change any mods you want to unload from =on to =off and they shouldn't load next time you start up Technic (this only works for SP tho).
I hope this helps.