I am currently testing openstack for windows guests (XP and 7). I have deployed openstack "all in one" on system with following specs Processor corei5. (4 physical cores and 8 Threads with HT Technology) RAM 8 GB. HD 500 GB. I have created 4 windows xp guests with 512MB RAM and 1VCPU. On each windows guest i have installed visual studio 2008 only. In nova.conf CPU Over-Commit ratio is 2 for better performance (as mentioned in openstack operation guide). Using KVM as hyerpvisor. I have observed poor performance when simultaneously using visual studio in four windows instances. How i can improve performance ? Should i use KVM or Hyper-V ? or any other suggestion ?