How in-depth are you going to be using CAD and such on this machine? I'm assuming you're an electrical engineering student at a university that has workstations avaliable for your use (most larger universities do). If you're no longer a student, and this is for your professional endeavors, I would definitely go for the T60p or Z61p models over the Z61m (as suggested above). I would also consider building a respectable desktop workstation instead of buying a mobile workstation unless you definitely need all that power on the go. Here are some things to consider if you buy a mobile workstation:
- Most of the time GPU's (IE: your graphics "card") is not replaceable in a mobile station (there are exceptions). If it isn't, you'll generally want to go with the best you can afford at the time. For CAD, the mobile fire GL discrete graphics will prove much better than an integrated chipset.
- For ram I would definitely try to stick to 1.5+ gigs...
- For HDD, go with the 7200rpm models. If you can't afford the increase in price to the 100gb model from the 60gb model, go with the 60@7200 and purchase a external drive later for your media. External drives can be picked up dirt cheap if you look around and catch the sales. A 250gb 7200rpm drive shouldn't run you more than $100 if you can pick up the drive itself for a decent price (I saw several 250gb deals for $50 recently).
If you're a student, many opt to buy a laptop + dekstop for school (not always at the same time). The nice thing about a desktop is, you can upgrade them easily when you have the money. A desktop built before your first year can easily last until you graduate 4-5 years later, though it might have completely different components in it when you graduate (that's what sales are newegg are for). And again, since I'm not sure if you are a student (you could already be in the field for years for all I know), take this advise for what it is. I've personally found that while at school, most of my intense CAD/matlab/etc... work was done on the university's workstations either while in class, or in group environments after class with classmates. You might not need some fancy workstation at all, but I would recomend talking to someone at your school that's in said major before you purchase a high end machine.