A methodological computing application and well known artificial standard, the Linpack algebraic library has been used to evaluate the concert of cloud infrastructure. Using this function the enactment of several key aspects in cloud computing such as the pressure of the number of Microsoft virtual pcs in work per host, as well as the I/O operations were evaluate. Linpack benchmark was executed under different pattern of the physical host, with different problem sizes and with or without hyper-threading, and with the Microsoft virtual PCs managed using the Microsoft virtual PC hypervisor.