If you are going to purchase a new computer (or make it yourself), you should definitely think about graphics — for CAD/CAM, gaming, searching for extraterrestrial intelligence at home or password cracking. Of course, thinking of budget, too. I hope you’re already aware of NVIDIA SLI which allows to use multiple video cards, but how a single dual-GPU compares to two single-GPU ones? Read GeForce GTX 295 Vs. GTX 275 SLI: When Two Are Better Than One.