Cringely's Shameless Self-Promotion
wild_berry writes "The latest edition of Bob Cringely's column at pbs.org, entitled Shameless Self-Promotion: Bob's Disk Drive is up. He's talking about replacing the glass or metal platters in present hard disk drives with foil platters in order to save energy." From the article: "The materials cost more but we use so much less of it (the disk is so incredibly thin) that the total material cost is substantially less. This 'floppy' material has the same kind of magnetic coatings used on standard disk drives and our drives live on the same technology growth curve as those others. The way we obtain greater storage density is simply by putting more platters in a drive (say 12-15 instead of 4-5 in an enterprise 3.5-inch drive) because they are much thinner and can be stacked closer together. The only parts of the drive that are significantly different are the platters and the heads and the heads vary only in having an extra slot."
Get out the tin foil...umm.. okay, it's alrealdy in there
Ideally, the disks would be spinning so quickly that the outward force would keep them almost perfectly flat. Assuming the disks were very smooth and the internal atmosphere of the drive is gas-only (no dust - a safe assumption) there would hopefully be very little turbulence within the drive to cause fluctuations in the flatness of each platter.
In my lab we coat floppy materials (like plastic) in a spin coater at several thousand RPM. At that speed the disk may aswell be rigid.
Forgot to mention, the reason film isn't used is the coefficient of expansion. There's no temperature regulation in drives (yet) and there isn't a film material in existence that doesn't expand and contract with the temperature. That's actually one of the reasons glass was introduced awhile back, data densities were getting so high that even the rigid metal platters were moving enough to become a factor.
In particular, I'd like to see evidence for the following claims:
I'd sure like to see the assumptions and numbers underlying that equation. Gee, Cringe, which do you think costs more: The raw platters themselves, or the read/write heads? I would say the latter. So you're going to drop the costs of hard drives by doubling the most expensive component? Huh? Sorry, I'm not buying this at all. You don't think a non-cleanroom enclosure is going to result in data loss on the platters themselves? Even if you're not getting particles during the read/write phase itself, you're getting them on the platter. I'm not buying the logic here. Sorry, I'm not buying this at all. Until the advent of true Drexlarian nanotechnology, I doubt you're going to see a mechanical action (you still have to move the eread/write heads) beat an eletronic one (reading from Flash).I'm not saying that the technology Cringely talks about is impossible, I'm saying: A.) There seem to be a lot of unwarrented assumptions underlying his logic, and B.) Implementation always has unforeseen hurldes and obstacles that will make these drives seem like far less of a slam-dunk vs. current technology (or more specifically, where regular drive technology will be 18 months from now) than it appears.
Finally, once it is ready, I'd like to see real-world tests for speed/electrical consumption metrics with existing technology. There might indeed be some savings, but I seriously doubt they are as dramatic as Cringely claims.
Crow T. Trollbot
Now imagine what happens if you tilt the drive.
The hub now has to transfer a force rectangular to the foil-plattern's surface - fast - to tilt the rotating plattern inside the drive.
But the foil-plattern want to stay where they are (think bicycle wheel)
A foil doesn't provide much resistance rectangular to it's surface. The process is called "folding" if done exactly or "crumpling and head crashing" if done in a foil-platter-drive. Maybe it would even be called "cringling" then?
Do I make any sense to you?
Coincidently the CAPTCHA for this posting was "weakness"