Resource usage of Windows computer laboratories

Studies focusing on Unix have shown that the vast majority of workstations and desktop computers remain idle for most of the time. In this paper we quantify the usage of main resources (CPU, main memory, disk space and network bandwidth) of Windows 2000 machines from classroom laboratories. For that purpose, 169 machines of 11 classroom laboratories were monitored over 77 consecutive days. Samples were collected from all machines every 15 minutes for a total of 583653 samples. Besides evaluating availability of machines (uptime and downtime) and usage habits of users, the paper assesses usage of main resources, focusing on the impact of interactive login sessions over resource consumptions. Also, resorting to Self Monitoring Analysis and Reporting Technology (SMART) parameters of hard disks, the study estimates the average uptime per hard drive power cycle for the whole life of monitored computers. Our results show that resources idleness in classroom computers is very high, with an average CPU idleness of 97.9%, unused memory averaging 42.1% and unused disk space of the order of gigabytes per machine. Moreover, this study confirms the 2:1 equivalence rule found out by similar works, with N non-dedicated resources delivering an average CPU computing power roughly similar to N/2 dedicated machines. These results confirm the potentiality of these systems for resource harvesting, especially for grid desktop computing schemes.