A method, system and processor for substantially reducing the write penalty (or latency) associated with writes and/or destaging operations within a RAID 5 array and/or RAID 6 array. When a write or destaging operation is initiated, i.e., when modified data is to be evicted from the cache, an existing data selection mechanism first selects the track of data to be evicted from the cache. The data selection mechanism then triggers a data track grouping (DTG) utility, which executes a thread to group data tracks, in order to maximize full stripe writes. Once the DTG algorithm completes the grouping of data tracks to complete a full stripe, a fall-stripe write is performed, and parity is generated without requiring a read from the disk(s). In this manner, the write penalty is substantially reduced, and the overall write performance of the processor is significantly improved.