3D Max ( like most CAD orientated software ) renders by computation. The actual screen visualization is a minor part of the workload.
In other words, you need the fastest possible processor that your budget will allow.
A quad 4 is of little value to you unless you run other programs in the background while you draw: clock /memory speed is much more important. Make your machine at least a dedicated workstation with a Core 2 Duo and don't load too many other programs on it.
If you have a heap of money get a Intel® Core™ i7 Processor with the latest motherboard to suit. Add an Nvidia GeForce 6800 Ultra graphics card, at least 4GB of RAM. Run at least 2@7200rpm SATA harddrives in RAID 0 - striping ( since the program tends to run on the drives )
Nvidia GeForce 6800 Ultra is "Shader Model 3.0" compliant, and 3D Max uses Shader Model 3.0 programming. Buy a graphics card with this protocol.
If you don't have a heap of money, buy the machine with the fastest processor you can afford, get a nominal graphics card and set the program graphics defaults to "OpenGl" rendering.
If you have a networkable version of 3D Max, it's sometimes worthwhile "nesting" a number of machines. If you can run multiple versions of the software on different machines, it's possible to chop up your animation job between the computers. You could try drawing in layers, or farm out separate scenes for raytracing to each computer on the network. In this way, machine speed is not so important since you can leave the "background" machines running 24/7 rendering while you build your models on the main workstation. Go to an auction and pick up a stack of ex-govt pentium4's and a decent router. You will need to become very efficient at working on multiple machines to make this worthwhile.