A method for determining an aging period for retaining a write-back data in a cache memory prior to writing the write-back data to a storage media is determined through use of a write-back aging routine. The aging period is based on a proportional utilization level of the cache memory by the write-back data, the higher the memory utilization level, the shorter the period for aging the write-back data. The aging period takes a form of an aging threshold, which differs depending on the memory utilization level, i.e., the amount of cache memory utilized by the write-back data.The method includes, identifying the memory utilization level, selecting the data aging threshold based on the memory utilization level; and writing the data from the cache memory to the storage media when an age of the data in the memory exceeds the selected data aging threshold.