[saticmotion]

If it behaves like RAM, from the POV of the OS, I'd imagine the advantage to be the large size. There's also the fact that it won't lose its data on power loss.

Of course, if it behaves like a regular SSD, the read speeds still exceed SATA3.0 speed.

[tfb]

> There's also the fact that it won't lose its data on power loss.

Does this mean that for software to take full advantage of this, the software will need to be updated to account for it? For instance, Redis loads data into memory from disk upon starting, but if something like this 400GB SSD is available as memory (and say for instance, 300GB is in use by Redis), wouldn't it make sense for Redis, upon starting, to just "remember" the state of the memory rather than reloading it from disk?

[icebraining]

Not really; we already have suspension (to RAM and to disk), this can work just like it. For the userspace software, it'll be like it never stopped running.

[ars]

No, that's not correct. This is MUCH MUCH slower than RAM.

You would not use this to replace RAM, but rather have a second section of memory for persistent data.

[kalleboo]

In the hypothetical world where this was as fast as real RAM, it would be cool if the OS was smart enough to read mmap'd data onto it and deal with remembering "this file was mmap'd here and hasn't changed since, next time it's mmap'd again we can just reuse it", and instantly you have support for all the software that just uses mmap (comedy MongoDB option?)