Western Digital announced today that they have entered in to an agreement to acquire SanDisk for approximately $19 billion. Western Digital is one of the few remaining hard drive manufacturers, but their only presence in the solid state storage market has been the enterprise SSDs sold by subsidiary HGST. SanDisks joint venture with Toshiba on the other hand - one of the four major manufacturers of NAND flash - allows SanDisk to develop a wide range of solid state storage products. This acquisition will give Western Digital some much-needed diversification and potential for growth as hard drives are becoming a niche storage medium.

Without a major SSD-related acquisition, Western Digital would have faced diminishing relevance or the daunting task of carving out a significant piece of the highly competitive SSD market. Over the past several years the solid state storage industry has seen a lot of consolidation, leaving Western Digital with few options for acquisition, of which SanDisk was the largest they could afford.