Graphic Problems with Hypermesh

Hi all,

Right now i am working on a very complex geometry and my objective is to carry optimization for this model .I have meshed it using .5 mm element size and got 4,500,000 elements and now i have got a problem with grafik display option ,with this heavy model i am not able to work with it the usual way i.e. not able to rotate ,move the model the usual way and most of the features are taking ages to work.Kindly provide me a solution to proceed further ,i have tried working with the wireframe mode also but that also is slow.I cant reduce the element size and i have enough memory 16 Gb of ram .