Vmware can be configured to use all physical memory for VM’s or it can swap part or all of the memory needed to run them.
After upgrading to Karmic Koala and VMware 6.5.3, after 10/15 minutes of using the virtual machines, my work laptop computer (an HP nx9420) would grind to an halt as the internal disk was fully active. The Linux top command show some serious activity on the kswapd daemon, and the load average just jumped to above 8/9.
In practice the swapping made my laptop useless and sometimes had to pull the plug on the VM’s (!!!). The HP NX9420 has an old chip set, I believe 945M so it can’t support 4GB of memory, and only shows around 3.3GB of RAM available despite having 4GB installed.
So the solution? Just run vmware as root: sudo vmware and change the Settings->Memory, to not allow any memory to be swapped. The number of virtual machines that can be run now must fit to the memory value defined in this tab, but at least there is no swap activity and machines run at full speed.