So if Moore's Law has held for many years and disk drive capacities have been growing faster than Moore's Law, how did solid state drives ever get to the point where they are affordable in similar capacities?
I can get a 1 TB SSD for $279, the same capacity that is in my laptop which is only a bit over a year old.
-- Rick C
-- ----Android NewsGroup Reader---- http://usenet.sinaapp.com/
Well if HDDs grew faster than Moore's law then the 60 MB drive of 1989 would be 60 TB by now.
-- ----Android NewsGroup Reader---- http://usenet.sinaapp.com/
So we are pretty close to that, no? I have a 5 TB drive sitting on my desk. Or do you mean they would have to be bigger than 60 TB?
I looked this up and earlier disk drives were doubling in capacity every
18 months which then changed to every year. That is faster than Moore's law and anything we've seen in semiconductors. I did see a couple of references that said disk drive capacity has not increased much in the last few years though. Not sure why it came to a screeching halt. Perhaps a lack of demand? How many of us really need 60 TB drives?-- Rick C
Especially since they'd take a month to back up!
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
60 TB? YIKES! Given you can get 50 GB on the highest-end blu ray media, that would take 1000 blu ray disks to back up! UGH!
Jon
There are some "interesting" (in several senses of the word) issues that come up when you try to push hard-drive capacity much higher.
A lot of the problem results from the fact that at today's capacities, the physical size of each bit storage area (each individual magnetic domain) is *tiny*. The domains are so small that they're beginning to suffer from various magnetic effects, such as:
- thermal self-erasure. The amount of energy stored in each bit domain's magnetic field is so small that random (thermal) fluctuations can "flip" it, thus changing the stored bit.
- adjacent-track erasure. The bits are so small that it's very difficult to construct a read/write head whose electromagnetic field doesn't "fringe out" and affect adjacent tracks when writing. With today's drives, writing data to a sector actually weakens the field of bits stored in the adjacent track, and over time this causes the stored data to become harder to read. The drives have to spend a fair bit of their time "remembering" how frequently each track has been weakened by writes to its neighbor, and periodically reading the data back, moving it to a safe location, and then rewriting it "in place" to restore the data strength.
Look up "shingle recording" to see where things are going, as a result of this.
- physical fragility. In order to write smaller bits (closer together in both X and Y dimensions) and keep self-erasure down to just a nuisance, you have to have a smaller read/write head, and "fly" it closer to the platter. With less room between head and platter, the mechanical tolerances have to be finer and the head becomes more vulnerable to interference from "crud" (particles of dust, smoke, or debris from within the drive) on the platter.
And, yes, as you say, there isn't a huge demand in the consumer space for really huge drives. The ultra-high-capacity drives tend to be sold into the "cloud storage" market, moderate-sized-but-wicked- fast drives go into function-specific servers, and "operating system and personal storage" drives for home and laptop use that don't need such high capacities are becoming predominantly SSD rather than hard drive due to the speed and robustness advantages.
I back up hard drives to other hard drives.
-- Rick C
A TV-STB for recording all the TV-programs that you never have time to watch :-)
Yes, I'm doing this for daily backups, but I want some off-site and in the fire safe backups, too. So far, what I need fits on a couple plain DVD's, but it is getting tight. I'm looking at getting a blu-ray writer.
Jon
That's a function of the data you wish to back up, not the drive capacity. If you want to back up the entire drive the only really practical way is to another drive. That reminds me, I need to do a back up.
-- Rick C
If hard drives were still the same physical size as in 1989, 60TB might not be a problem, aside from the insane cost of such a large drive.
A few days ago I came across a box of full height hard disks in sizes from
760MB to 9GB. I still have some 23GB full heigh units and the largest made were 47GB in that form factor.
Customer got some SSD raid mirrored disks, against my advice. After losing a couple of them, they switched back to magnetic disk. I told them that they could pay for the most expensive SSD, but the chance of having a birthday is still 50/50.
I didn't know they made full height hard drives at a time they could make a 9 GB drive. Maybe you mean 3.5 inch full height drives. The old
5.25 inch full height drives were the size of TWO drive bays in PC towers. I thought they disappeared long before reaching 9 GBs but maybe not.-- Rick C
We do offsite backups onto terabyte USB drives. Once a month, we dump everything onto a drive, put it in a ziploc bag, and stash it in one of four offsite locations. They are used write-once, assuming that we'd ever only read one if we have a disaster to recover from. A terabyte USB drive is now about $55.
We have other backups for shorter-term stuff, nightly and weekly.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
It's more that the increase in capacity was driven by the discovery of giant magneto-resistance
I knew one of the guys that worked in the area - Theo Rasing - who got a (Dutch) Spinoza Prize. Nice guy.
Colossal magneto-resistance is something different, and doesn't seem to have been exploited yet
-- Bill Sloman, Sydney
Spinning rust mills have very high latency. No one wants them. Intel/Micron X-Point will also be available soon.
I do! And all the server farms do, too.
There is a long and tragic history of phase-change memory. This will be interesting.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Depends on what you're using them for. Their three shining virtues are (a) they don't wear out from read/write cycles; (b) they're much easier to erase reliably; and (c) they're much cheaper per GB.
Advantage (b) is related to the wear-levelling algorithms that flash needs to reduce its tendency to wear out.
I expect to be using HDDs for awhile yet. (BTW they haven't used iron oxide for a good 20 years.)
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
On Wed, 27 Apr 2016 19:58:39 -0700 (PDT), snipped-for-privacy@gmail.com Gave us:
"Spinning rust mills"? You're an idiot. Aluminum case, Aluminum platters, Stainless steel head arms. What's to rust, goofy child?
Magnetic disc "hard drives" are going to be around for quite a while yet.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.