I am working on spec'ing out a new laptop for work and have been looking at the Dell AlienWare M18xseries as it seems to have a good deal of power in the right places for a good price. What I am wondering is how well the following graphics cards will handle a large assembly that I regularly work with, the file size is about 30Mb and the assembly consists of 2616 parts with 689 of them being unique and that number is growing each day as I work on it.

AMD Radeon HD 7970M

NVIDIA GeForce GTX 675M

I have looked up a few benchmarks on the two processors but it seems that they are all geared toward gaming performance and not CAD performance for large assemblies. In these, it seems that the AMD Radeon 7970M blows the NVIDIA out of the water (and it's cheaper)

The specs for the other important hardware are:

Core i7-3820QM 8Mb cache up to 3.7 GHz w/turbo boost

24Gb Dual Channel DDR3 1600 MHz

500 GB 7,200 RPM Main Hard Drive with a 32GB mSATA Caching SSD

There is also the option to go with dual GPU's of either of these two if that would help?

I see that SW pretty much recommends the Quadro video cards but these dont seem to be available in the Precision workstation at a cost that is anywhere near the M18x (slower processor, less available RAM, expensive to get SSD drive) So it seems logical that if these graphics cards can handle the large assembly processing then the M18x is a much better choice.