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Phase Change Memory vs. Storage As We Know It
storagedude writes "Access to data isn't keeping pace with advances in CPU and memory, creating an I/O bottleneck that threatens to make data storage irrelevant. The author sees phase change memory as a technology that could unseat storage networks. From the article: 'While years away, PCM has the potential to move data storage and storage networks from the center of data centers to the periphery. I/O would only have to be conducted at the start and end of the day, with data parked in memory while applications are running. In short, disk becomes the new tape."
Ya, we had that back in the stone-age and Multics would have been poster-child for this type of thinking, but it was a *bitch* and made portability problematic. I think VMS has some of this type of capability with their Files 11 support - any VMS people care to comment. Unix (and most current OS) sees everything as a stream of bytes, in most cases, and this is much simpler.
An OS cannot be everything to all people all the time...
It must have been something you assimilated. . . .
Numonyx announced some good advances in PCM a few months back:
http://www.pcper.com/comments.php?nid=7930
Allyn Malventano
Storage Editor, PC Perspective
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From TFA:
Ya, we had that back in the stone-age and Multics would have been poster-child for this type of thinking, but it was a *bitch* and made portability problematic.
No, Multics would have been the poster child for "there's no I/O, there's just paging" - file system I/O was done in Multics by mapping the file into your address space and referring to it as if it were memory. ("Multi-segment files" were just directories with a bunch of real files in them, each no larger than the maximum size of a segment. I/O was done through read/write calls, but those were implemented by mapping the file, or the segments of a multi-segment file, into the address space and copying to/from the mapped segment.)
I think VMS has some of this type of capability with their Files 11 support - any VMS people care to comment. Unix (and most current OS) sees everything as a stream of bytes, in most cases, and this is much simpler.
"Seeing everything as a stream of bytes" is orthogonal to "a hint that the file will be read sequentially". See, for example, fadvise() in Linux, or some of the FILE_FLAG_ options in CreateFile() in Windows (Windows being another OS that shows a file as a seekable stream of bytes).
Nonsense.
Certainly "everything" won't be much faster - but we're always after faster storage. I/O is a very common bottleneck. Sticking everything in RAM will make a big difference to a multi-use computer.
IT really depends on the use-case - given enough ram, and a good caching algorithm, and a simple use-case, maybe it won't help once the cache is primed (say serving static content from a fast webserver). Everything ends up in RAM anyway.
But running a system from a fast SSD, or even from a ramdisk, as you say, leads to significant improvements in usability for general-purpose-ADHD-computer use. Apps load instantly.
To go back to the SSD example - more and more people are finding an SSD for a system drive makes things significantly faster, and ram-backed drives DO make databases much faster.
Sure, it won't make the network faster - and if everyone actually bought *enough* ram for the task at hand, caching would take care of it, but for some reason, you know, most poeple don't.