LFCS: Preparing Linux for nonvolatile memory devices

> Why are you assuming that the NVM will separate from the main memory subsystem like NAND is currently?

> Even if this NVM is on the same DDR socket, they seem to say that the number of writes is limited, and the time it takes to write NVM is longer.

There is several different types of NVM (Non-Volatile Memory), and while some have a limited number of write-cycles, others don't. Performance also vary, and several types are faster than DRAM (currently used as main memory), though to my knowledge none are quite as fast as SRAM (currently used as CPU cache).

That said, there is going to be a while before you can get anything with both good performance and unlimited write-cycles for anything resembling the price of regular DRAM, so while I expect some type of NVM will eventually be used in the main memory system, we are going to need some other system in order to use the current, imperfect, NVM types in the meantime...