(see details) Can my machines handle this?

I have a small home network consisting of two clients and one server. I really need to practice subnetting for an upcoming test. Both computers run Windows 7 Professional, and the server is running Server 08. I was thinking of using MS Virtual PC to create about 8 virtual computers on each host computer. Then I can take a single network address and practice subnetting to make a few networks with a few hosts on each. I know I have enough ram for this if I use a lighter OS, like Win2k or WinXP on the VM's. What I do not know is how the processors will handle the extra load of that many virtual computers running on Dual Core Pentiums. One is x64, and the others are x32. Also, will the network cards get mad at me for networking 8 VM's per NIC, and have the host OS's on the other (real) network?