I have asked this question on SO, but was suggested that i ask it here on SF, so here it goes.

http://stackoverflow.com/questions/3010753/wastage-of-resources-in-virtualization

I am not sure if this is the right place to ask the question. However i hope it is.

When looking for a VPS earlier today, I was trying to understand how each container would work in the background. Keeping in mind the fact that the operating system uses most of the memory and power on a system, wouldn't having multiple operating systems in the same machine mean more wastage of resources.

For instance if i was running centOS on a dedicated box and it was running lets say 20 background OS level processes. Then i go and install a virtualization platform and install 5 more centOS virtual machines in the same system which are exactly the same as the host operating system. Doesn't this mean duplication of those 20 processes 6 times? So internally the context switching is happening between 120 processes instead of 20?

Further Notes: Here is an example of what i am thinking: I have a master-slave configuration for a long running, cpu + memory intensive process, which can be distributed to 4 machines. Lets say when the process runs on these 4 machines with lets say 1 Gh CPU and 1 Gig RAM, i get 400 results per hour from the cluster (assuming 100 results from one machine) . Now i get a bigger machine ( lets say 4Gh and 4 Gig RAM), have 4 virtual hosts on it with 1 Gz CPU and 1 Gig RAM. Will this configuration give me the same 4 results per hour from these 4 virtual hosts?