^+1 for above 2 posts. We need more info. Also answer these:
1. How big are the renderings?
2. Which version of 3DS Max (ie 3DS Max 2010,etc)? 32 or 64 bit?
3. Do you use any CUDA accelerated plug ins such as Ruins?
4. Max total Budget? Do you need a new LCD?
5. Is this for pro level work?