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Maybe this is obvious to those working with this, but did something change about what "NVM" means aside from "non-volatile memory", i.e. what "Flash" memory is?

Maybe this is obvious to those working with this, but did something change about what "NVM" means aside from "non-volatile memory", i.e. what "Flash" memory is? Is the assumption that "NVM" == "NVMe" or?

geeio 8y ago
NVMe is the spec for controllers supporting NVM. Think PCI vs PCIe https://en.m.wikipedia.org/wiki/NVM_Express https://en.m.wikipedia.org/wiki/NVM_Express
- theincredulousk 8y ago
  Thanks. I guess that still doesn't clear up why the whole article considers "Flash" and "NVM" as two distinct technologies/concepts/whatever. Edit: even on that wikipedia page: "The acronym NVM stands for non-volatile memory, which is often NAND flash memory" I feel like I'm taking crazy pills here
- Dylan16807 8y ago
  > Think PCI vs PCIe That's even more confusing because those are basically two implementations of the exact same thing, but separated by a decade of tech improvements.
digikata 8y ago
It's essentially a little bit of industry jargon. Flash is non-volatile, and can be available via an NVMe interface. NVM in this context references essentially, some faster-than-Flash non-volatile memory. Since there are multiple tech contenders for this class of NVM, papers often leave it unspecified; but it can range from battery/supercap backed DRAM to PCM, to whatever Intel is using for Optane, or STT-MRAM, or others. Even more confusingly, NVM can be available over NVMe as block access or memory bus interfaces as "byte accessible", or even byte accessible on a memory bus transformed into block access software interfaces, and then there are other PCI level interfaces too. So you can think of NVM in this paper as something like at least an order of magnitude faster than flash access.
wmf 8y ago
In this case NVM means Optane SSDs. In general, the term NVM has become so muddied that it's a waste of time to explain it.

geeio 8y ago

NVMe is the spec for controllers supporting NVM. Think PCI vs PCIe https://en.m.wikipedia.org/wiki/NVM_Express https://en.m.wikipedia.org/wiki/NVM_Express

theincredulousk 8y ago
Thanks. I guess that still doesn't clear up why the whole article considers "Flash" and "NVM" as two distinct technologies/concepts/whatever. Edit: even on that wikipedia page: "The acronym NVM stands for non-volatile memory, which is often NAND flash memory" I feel like I'm taking crazy pills here
Dylan16807 8y ago
> Think PCI vs PCIe That's even more confusing because those are basically two implementations of the exact same thing, but separated by a decade of tech improvements.

digikata 8y ago

It's essentially a little bit of industry jargon. Flash is non-volatile, and can be available via an NVMe interface. NVM in this context references essentially, some faster-than-Flash non-volatile memory. Since there are multiple tech contenders for this class of NVM, papers often leave it unspecified; but it can range from battery/supercap backed DRAM to PCM, to whatever Intel is using for Optane, or STT-MRAM, or others. Even more confusingly, NVM can be available over NVMe as block access or memory bus interfaces as "byte accessible", or even byte accessible on a memory bus transformed into block access software interfaces, and then there are other PCI level interfaces too. So you can think of NVM in this paper as something like at least an order of magnitude faster than flash access.

wmf 8y ago

In this case NVM means Optane SSDs. In general, the term NVM has become so muddied that it's a waste of time to explain it.