People often say SSDs are expensive. But they're assuming that the capability of a hard drive is some scalar value (storage capacity) that makes it easy to comp

People often say SSDs are expensive. But they're assuming that the capability of a hard drive is some scalar value (storage capacity) that makes it easy to compare SSDs to spinning rust. The fact is, if you care about IOPS, SSDs are cheaper than spinning disks. In other words, you need to stripe out across way more spindles (and thus consume a lot of power) to get the IOPS you get from a decent SSD.