Help to speed up blender with new computer

I have been using blender on my new pc for a while but im not sure blender is using all the system and video ram I have available for it, when I use soft bodies or a mesh with about 1.5 million tris and 800,000 faces the viewport slows down some. I have thought about using Blenderbuntu v.2 instead of Windows 7 pro has anyone got great results from it?

When blender slows down I check task manager and it is only using a small fraction of available ram, I am using 64GB of 1866MHz and a GTX Titan 6GB running from an SSD… is there something I have to do to let blender use all the video and system ram to speed things up?

I forgot to say I have a i7 4930K CPU and an asus rampage IV black edition mobo all running at stock clocks - no overclocking

Bump - is Blenderbuntu v2 (Ubuntu) going to be much faster with renders than windows 7 pro? Is it worth using it, I don’t know if there is something better now than Blenderbuntu maybe some sort of Linux cut down version but how is everyone going on operating systems other than that of Windows?