A system, method and computer-readable medium for balancing access among multiple logical partitions to the physical system resources of a computer system employing system virtualization. Each of the logical partitions is classified, initially during a startup period, in accordance with a level of allocated dispatch window utilization. Performance metrics of one or more of the physical system resources are determined in association with one or more of the logical partitions. The performance metrics determination is performed at a hardware level independent of programming interrupts. During a dispatch window in which a given set of the physical system resources are configured for allocation to one of the logical partitions, the given set of physical system resources are re-allocated to a replacement logical partition in accordance with the determined performance metrics associated with the replacement logical partition and the dispatch window utilization classification of the replacement logical partition.