CWA107 Thanks for the insight. However, if I do run the CAD using boot camp I will not be able to be on both at the same time? I'm not exactly sure how to do all this it is a challenge to do the IT side of my business. I'm a kitchen and bath designer and so I'm forced to confront computer issues and so here I sit not even really understanding your suggestion completely but I certainly don't expect you to take the baby steps I need to understand
I will try to break this down and make it simpler...
VMWare Fusion, Parallels Desktop and VirtualBox are all different products that fall into the same category of software, known collectively as "virtualization". What they do, in layman's terms, is create a "pretend" PC within a process running on your computer. Since that "pretend" PC doesn't have access to the hardware resources of your computer, it has to go through layers of software to do that. As a result, the performance will never be quite up to par with running a software package on the system itself (we refer to this as "native").
Your Mac, from a hardware standpoint, is like any other run-of-the-mill PC, albeit with a few Apple-specific tweaks. So, it has the ability to run Windows natively just as any other PC would. Boot Camp is a set of tools that facilitate this process and sets it up in such a way that Mac OS X is still available.
In other words, when you configure Boot Camp, you give your Mac a split personality, such that you can choose to start it up in Windows or in Mac OS X, but you can't run them both at the same time as you can under VMWare Fusion.
So, what are your options for optimal performance? My vote would be to look at a Mac-specific software package for your CAD work. There are a number of great options out there, most specifically, AutoCAD, which is sort of the standard-bearer for the segment. If you don't need something that high-end, you might try looking at packages like iDraw or one of many others available on the Mac App Store when you search for the term 'CAD'.
Aside from that, you can run it straight from Windows via Boot Camp, but of course, then all your Mac goodness is unavailable until it's time to reboot (as you rightly noted).
And finally, you could continue to try to tweak around with settings in VMWare, but I really don't think that's going to help. Specifically, I would allocate at least 4GB of RAM to the VM if the package you're using is 64-bit. If it's 32-bit, then it can't address more than 3GB of RAM anyway. Also, under the Graphics settings, make sure that 3D acceleration is enabled. You might also try allocating an additional core or two under the processor settings - but that is just "pretend", so it probably won't help a whole heck of a lot.
You might also try Parallels Desktop, as it is supposed to be a bit more capable in terms of 3D performance, but I think that is mostly geared toward gaming - and Parallels tends to be less reliable as well.
Hope that makes sense.