Now that my Dell Machine has a lot of RAM (8 GB) and hard disk space, it is quite easy to run 4 virtual machines at the same time, each one utilizing 1 GB of RAM, 2 cores and/or threads, 3D acceleration with 128 MB of video RAM. Windows XP also has 2D acceleration on. Arch Linux also has guest additions installed with GNOME 3 performing almost perfectly. By saying almost, I mean, it has awkward full screen behaviour. It might be a bug in GNOME’s virtual box support.
All of these and still having almost 2 GB free. And not only that, I am also running Vuze torrent client (a.k.a. Azureus), Skype, Opera, Clementine and various backround programs.
In the screenshot you can see four VirtualBox machines, Arch Linux, Backtrack 5 R1, Backbox 2.01, Windows XP Performance Edition
Look at the top of my current desktop, the Core Temp gadget:
Bellow a screenshot of the Windows Task Manager, Processes tab:
What is your success with VirtualBox, or VMware?