CPUs, GPUs, chipsets, motherboards, RAM, Wi-Fi, and all the other components you think of when you think about a PC have all been getting continuously faster over the last five years, but so far this decade nothing has offered the performance boost of a solid-state drive. Putting an SSD in a five-year-old computer is enough to make it feel like a new machine even if every other component stays the same, and at this point you're really doing yourself a disservice if you're buying a new machine without one.

However, pricing for SSDs has always been higher than pricing for HDDs of similar or larger sizes—a 1TB desktop or laptop hard drive will typically run you somewhere between $50 and $80, and for that kind of money you can still only get a 120GB or 240GB SSD. Pricing has fallen a long way in recent years, though. According to data from DRAMeXchange reported by Computerworld, average pricing for SSDs has fallen from about 99¢ per GB in 2012 to around 68¢ in 2013 and about 39¢ in 2015.

Falling NAND prices and healthy competition should keep prices tumbling over the next couple of years, too. DRAMeXchange projects that pricing will fall to about 24¢ per GB in 2016 and to 17¢ in 2017, lowering the average price for a 1TB SSD to about $170. This is good news for upgraders, but, over time, falling prices will slowly spur adoption in new PCs as well. Most of the volume in the PC business is at the low end, and cost-cutting OEMs still ship HDDs in the bulk of those systems—only about 25 percent of new consumer PCs currently come with SSDs installed, according to DRAMeXchange's data, and that number is expected to rise to 31 percent in 2016 and 41 percent in 2017.

By comparison, HDD prices seem to have more or less bottomed out, moving from 9¢ per GB in 2012 to 6¢ per GB this year (and remember, hard drive prices in 2012 were still inflated somewhat from the flooding in Thailand the year before). That 6¢ per GB baseline isn't expected to move much in the next two years, but HDDs aren't really getting dramatically faster these days either. By contrast, SSDs continue to improve dramatically as new NAND technology and faster PCI Express-based connectors and interfaces are introduced.