For decades, the goal has been to create a random access memory (RAM) that is non-volatile like flash storage but with the speed and addressability of a RAM chip. Such technology would dramatically change programming methods providing its cost was in line with flash memory storage chips.
The NAND flash memory commonly used in solid state drives (SSDs) is non-volatile. Like a hard drive, data are written and read in large chunks (see
sector). RAM is much faster, and any single byte can be written, read, calculated, compared or copied independent of all the other bytes (see
byte addressable). However, RAM is volatile and loses its content when the power is off. See
storage vs. memory,
flash memory and
chips vs. disks.
Available from 2017 until 2022, Intel's Optane chips were an example of non-volatile RAM, but Optane was more costly than the flash memory in SSDs (see
3D Xpoint).
A Paradigm Shift in the Future?
The interplay between main memory (RAM) and storage is how computers have operated since the 1950s. Software and data are copied to RAM from storage, and updated data are copied from RAM to storage. If storage were as addressable and as fast as RAM, the program and all processing could take place in storage. Computers would always be "instant-on."
However, that shift is likely to be decades away. Although non-volatile, byte-addressable RAM memories are increasingly used as caches and as main memories in small devices, NAND flash storage chips are always getting faster, more dense and less expensive. See
non-volatile memory.