Home > Storage > PowerMax and VMAX > Data Protection > Dell PowerMax 2500 and 8500: TimeFinder SnapVX Snapshots and Clones > Snapshot performance
I/O profile and snapshot count are both factors of performance. A snapshot delta is created the first-time protected data is updated after a snapshot is taken. PowerMaxOS will use either redirect-on-write or copy-on-write to accept the new data and create the snapshot delta. Full-track (128 KB) updates are written without other internal operations. For partial-track updates, the remainder of the data is read into cache and then the updated version is written.