I regularly hear people, including many that should know better, predicting that in just a few years we’ll evict all the hard drives from our data centers as SSDs become less expensive than spinning disks. While the decline in SSD prices has been dramatic over the last year or so, I’m betting that hard drives will still be going strong in 2020.
Today, if you shop carefully online, you can buy a general purpose enterprise SSD, such as Intel’s DC S3700 for about $2.65/GB or a read oriented drive like the Intel DC S3500 for $1.30/GB. By comparison, a 4TB nearline SATA hard disk such as Western Digital’s RE or Seagate’s Constellation cost under $400 or $0.09/GB. Interestingly, consumer/laptop SSDs are well below the magic $1/GB level with Crucial’s M500 selling for about $0.59/GB — about what hard drives cost in 2005.
Over the past few years, flash memory prices have fallen at an average of 35% a year. Hard drive prices declined at a similar rate or even greater rate in the past, but the trend has flattened out of late. In part, this is a one-time perturbation caused by the flooding in Thailand two years ago, which caused a shortage of both drives and drive components. Prices have just recently returned to their pre-flood levels as the drive vendors have re-filled their supply and distribution channels.