Determining the Real Capacity of a Desktop Cloud

Computer laboratories at Universities are underutilized most of the time [1]. Having an averaged measure of its computing resources usage would allow researchers to harvest the capacity available by deploying opportunistic infrastructures, that is, infrastructures mostly supported by idle computing resources which run in parallel to tasks performed by the resource owner (end-user). In this paper we measure such usage in terms of CPU and RAM. The metrics were obtained by using the SIGAR library on 70 desktops belonging to two independent laboratories during the three busiest weeks in the semester. We found that the averaged usage of CPU is less than 5 % while RAM is around 25 %. The results show that in terms of the amount of floating point operations per second (FLOPS) there is a capacity of 24 GFLOPS that can be effectively harvest by deploying opportunistic infrastructures to support e-Science without affecting the performance perceived by end-users and avoiding underutilization and the acquisition of new hardware.