The hard drives would have ironclad firmware that keeps the RAM refrehsed until its battery goes down to 15% (or whatever the conservative 10 minutes of power is), at which point it takes the ten minutes to dump the contents of that RAM to SSD, and reverts to having that drive also be SSD until the power is reconnected long enough to charge battery back up to 80%. Then it reads it back into RAM and continues as a Lightning Fast 64 GB + Very fast 16 TB drive.
You would store your operating system on the lightning-fast drive.
The absolute nightmare failure state isn't even that bad, as even though the RAM drive should be as ironclad as SSD, in case it ever should lose power unexpectedly through someone opening the device and disconnecting the battery or something, it can still periodically be backed up, so that if you pick up the short end of six sigma, you can just revert to reading the drive from SSD rather than RAM and lose, say, at most 1 day of work.
thoughts? I bet a lot of people would be happy to pay an extra $800 to have their boot media operate at DIMM speed, as long as the non-leaky abstraction is that it is a physical hard drive, and the engineering holds up to this standard.
There is a lot of software out there that is very conservative about when it considers data to be fully written - it would be quite a hack for Samsung to hack that abstraction by doing six or seven sigma availability on a ramdrive with battery and onboard ssd to dump to.
It would be very interesting to see a similar product being introduced using contemporary technology, though. One question is what sort of interface it would communicate over to leverage the higher transfer speed.
I think it is fine not to have any higher interface to leverage the transfer speed. RAM latency and speeds can obviously saturate disk interaces, but I doubt SSD's come close. So it should be a large jump in performance regardless.
Relying on a drive controller might seem the right way to go but especially for corporate installations I would believe it would be beneficial to have the fine grained control a dedicated server could provide.
I should have said "C: drive"/"HDA1" but wrote boot media so I could save having to think about my phrasing. I meant that's where you would install anything that is primary to your workflow and might read and write lots of files, because that's how it was programmed, git, your ide, compiler, test suites, database, webserver and log files, or whatever programs you create and handle your workspace with, whatever that may be (photoshop, design software, etc).
the point is, things you would never risk not having on permanent storage, and which are written with the expectation that they will be. if it's ironclad (six/seven sigma, and backed up to real permanent storage behind the scenes in case worse comes to worst), you wouldn't have to give up this abstraction. it would still be a hard drive and not, you know, the current contents of your ram since you booted.
Lastly if you do care about data retention during power outages and sags then you would likely want an APC/backup battery. Even though the data stored in the SSD/RAM hybrid might have enough backup power to flush to disk how about the data that is currently in RAM waiting to be flushed as well?
If it did, SSD's wouldn't be so much faster than spinning-platter HDD's...
By the way, what you're proposing in terms of software has been available for a long time; multiple distros (including Ubuntu) can/could be booted completely to RAM, using tmpfs as the filesystem. For example:
At the boot prompt, type "knoppix toram". Knoppix will load the contents of the CD into ram and run from there. After boot up, the CD can be removed and the cd drive will be available for other uses. Because this will take up a lot of ram, it is recommended for those with at least 1 GB of ram.
It's definitively faster, I just don't have the necessary RAM to fit all my system in there.
If it were all in a sealed package that 'guarantees' the RAM will never power down, at a very low firmware level, that is a different matter.