Pure play storage suppliers EMC and NetApp are outpacing the server and storage system players Dell, HP and IBM, with Compellent, 3PAR, Storwize and XIV the main catch-up bets for the three followers. Dell bought Compellent to expand its enterprise storage business in roughly the same way that HP bought 3PAR. We can fit IBM's purchase of XIV and Storwize into the same mould. Stifel Nicolaus analys