1. A method of providing cache management in a parallel processing system, comprising: estimating a residency time of a first data block that is not stored in the parallel processing system but is to be stored in the parallel processing system, wherein the residency time is determined when the first data block is not stored in cache at least partly based on an estimation of time required for the first data block to be resident in the cache of the parallel processing system; calculating a metric for the first data block at least as a function of the residency time and size of the first data block as the inverse of size of the first data block multiplied by the residency time of the first data block and adjusting the residency time based on a workload priority associated with the first data block; evaluating one or more data blocks in the cache by comparing a respective metric of the one or more data blocks with the metric of the first data block, wherein the respective metric of the one or more data blocks is at least indicative of their respective sizes and estimated residency times determined at least partly based on respective estimations of time required for the respective one or more data blocks to be resident in the cache of the parallel processing system; responsive to evaluating the one or more data blocks, determining to store the first data block in only one of the cache and a disk drive.