Why Not Solid State Hard Drives?

I never quite thought I'd see this in my life time, but RAM is now cheaper when it comes to memory-per-unitofcurrency than hard drives. Of course, those of you who have noticed this have also wondered, quite reasonably, that it might be cheaper to start building Solid State Hard Drives entirely out of RAM, rather than using the standard ole platters. Is there anyone in the market who also has noticed this and is attempting to market a product that will fill this need? Remember this puppy from 2 years ago, and this story, mentioned a year ago? While the first one was a bit of a laugh, the second article does mention a limit to the lifetime of the current MO Hard Drives. Are we closing in on that limit, now? Update: 10/11 2a EDT by C :I apologize for not catching the erroneous statement above, earlier. What I had meant to say was that since RAM is at its cheapest point in price in recent years, not to say that it was cheaper per-unit-of-currency, which is absolutely false. Chalk this one up to too much creative writing in college, lack of sleep, and a long frustrating day. Thanks to brian@pongonova.net for pointing out that error.

waterlogged asks: "I was just wondering if anybody has heard of a cheap ram based network drive? Seems to me with the ram prices being at about US. $12.00 for 128 megs that someone hasn't developed a battery backup version of this to plug into a network or even a bus. A gig worth of 8ns seek time storage for $120 anyone? That would just about eliminate any wait in loading programs."

BigSlowTarget asks: "There are some previous articles on Slashdot about vendors selling solid state drives, but they all seem to be quite expensive - particularly given the slide in the cost of memory. Has anyone hacked together a solid state drive to take advantage of $60/GB memory prices? I'd really like to be able to boot and run at solid state speed without spending thousands."

Jah-Wren Ryel asks: "In case you haven't noticed, RAM is incredibly cheap, you can put a gigabyte of PC133 RAM into your machine for less than $60. A year ago, that would have cost more like $600. So now it is feasible for one to have a 10-15GB RAM disk, except for one thing - most motherboards won't support more than 2GB total (4 dimm slots x 512MB per dimm). It seems like it wouldn't be too hard to design a PCI card to hold 20-30 dimms and make that available through a hardware windowing scheme (like EMS/EMM back in the old 16-bit days). With the right drivers it could be used as a big RAM disk or for buffercache. Is there such a product out there? The closest I have seen are solid-state disks that sit on the other end of a scsi bus, are too expensive, and aren't anywhere near as fast as a PCI implementation could be."

So what technical details (and the issues of volatile data and price) may be preventing the construction of RAM based drives, and is there anything else that may be preventing some entrepreneurial soul from bringing such a thing to market?

Comments

Re:Not a problem

[smallpaul]

Given the plummeting price of high density/small footprint hard drives, you could have both the volatile drive and the nonvolatile drive in a single low price unit, with backup to/recovery from the nonvolatile drive occuring automatically on startup and shutdown.

It needs to be more often than startup/shutdown! Many of us don't shutdown for weeks at a time. You would want it to continually copy things to the disk when there is idle time. But then you're essentially using the RAM as a really big disk cache which is where we are already today.

As I read the article, the whole point is to shift to RAM and save money at the same time. If you're buying the hard disk anyhow then you're shifting to RAM but not saving any money. And you may not be improving performance much over a massive RAM cache either. So I find it hard to be enthusiastic about this idea of backing up the RAM to hard disk.