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Next Wave Of Hard Drive Tech: Perpendicular Recording
angrytuna writes "New serial technologies are set to replace standard SCSI and ATA (Advanced Technology Attachment) interfaces over the next two years, even as hard-disk drive manufacturers prepare for an entirely new form of bit storage. Perpendicular recording will replace longitudinal recording in storage devices, placing bits on end instead of lying them parallel on the disc surface, thus dramatically increasing the possible storage density."
Does anyone have a link to a description of this that's more detailed than "stacking bits on end"?
Are they using platters with trenches and storing information on the sidewalls?
Are they using some means of reading and writing at many depths within the platter without disturbing other layers?
The article says the technology has been under investigation for 20 years, so presumably there's a forest of technical literature on it.
This conversation with Jim Gray, head of Microsoft's Bay Area Research Center, has grim, eye-opening comments on the growing gap between storage densities and access speeds/bandwidth. Currently the most effective way to send a multi-terabyte disk array is by UPS -- turns out a UPS truck has a "bandwidth" equivalent to about 7 megabytes/second. And the problem of practical access speeds is only going to get worse. At current and near-future access speeds, searching a 20-terabyte disk might take a year.
Storage density is one thing, but storage speed is another. With 200 GB hard drives readily available, and relatively cheap, the main thing I'm itching for is increased access and transfer speeds. Not just the controller speed as most hard drives still only maintain a constant transfer speed of 33Mbps. Theoretically, a denser drive at the same rotational speed will transfer data faster than a less dense drive, but will we see a dramatic improvement in sustained transfer speeds? While this transfer speed is acceptable while watching a DivX movie, it's really a pain while ripping a DivX movie. (A movie that I shot in my backyard, and authored, and own the rights to, and am ripping for the pure exitement as I would never violate a copyright.)
Not having to compress video and audio, thus not degrading the quality, is one use we would not mind having. It is good for both pros and average users alike.
Choosing the lesser of two evils is a choice for evil.
I'd like to see Redundancy And Speed hit the consumer market more than the current volume. RAID 0+1 should be standard in at least mid level systems.
Well, higher density means the same storage in a smaller form-factor, which means the read/write heads have to travel a smaller distance (both radially and logitudinally), which should yield a measurable boost in potential performance... no?
- Spryguy
There are three kinds of people in this world: those that can count and those that can't
More relevant than this technology that is still many years away, I find much more interesting the part about the desktop industry moving to 2.5" drives. So in the next year or so we'll be able to buy very high density, fast drives that can fit in a pocket and already have serial interfaces! All we need are sata jacks on the front panel and the world moves one giant leap closer to true "plug-n-play" goodness. Mail order sneakernets just got even cheaper!
I just stopped on the way home and did some photo shooting. I took 57 photos in about an hour. At 7.2MB per shot, that amounts to ~414MB of files from just an hour of shooting.
Post-editting results in TIFF files that are approximately 10MB in size. All told, this one shoot now occupies over 800MB on my fileserver - from just one hour of shooting.
Oddly enough, people do in fact use vast amounts of storage space for reasons other than sharing mp3s and movies. As technologies improve (cameras increase resolution, video cameras likewise, millions of other reasons), the demand for space will increase as it always has done.
One of the first Sun machines I used was a 3/160 with an external gigabyte disk array. The array was a washing machine size enclosure with a pair of 800 MB SMD disks with 8" platters. In 1994 this was a huge disk, in more ways than one!
Interestingly, my little 486 with its 340 MB drive were far faster than the old Sun, and even competitive with the newer SparcStations. 7200 RPM baraccudas in modified enclosures (extra fans and breathing holes made the difference between life and death) were even faster when they arrived.
After working exclucively with laptops for the past two years, I can see a clear parallel between the old 2.5" -> 2.5" transition and the 8" -> 5.25" -> 3.5" transitions in the past. Sure I keep a pair of 120 GB 3.5" disks in firewire enclosures around, but the 60 GB disk in my powerbook and the 30 GB disk in my Dell i8000 are more than adequate for daily use. My ipod even has 30GB, which is enough for my favorite music, the Warthog Jump video and a few other fun things.
With emphasis on blade and 1-U servers, as well as cardcage oriented telecom gear, I can see a lot of value for 2.5" disks in the telecom and server markets.
You know, drive technology IS backup technology. Just backup data to hard drives instead of tape or CDs. Also, I believe a big reason is the density of data. No longer can you have something like floppies, where punching a tiny hole in the media won't cause a problem. Now, a speck of dust making a tiny microscopic scratch would ruin megabytes of data on a HDD platter, so they can't make unsealed media like DVDs or tapes that dense, now can they?
I personally never understood why sealed media never got popular. CDs with caddies would be far better, but people stuck with bare-assed, easily damaged CDs instead. Same problem with DVDs. Minidiscs aren't very popular unfortuanately.
It's possibly that tightly sealed media could be much higher capacity than currently seen, but who's going to be the one who suggests to their boss that they should try doing something that has failed every other time it has been tried?
Zip-style disks could potentially provide very high capacities, but they can't expand as quickly as hard drives... To do that, you'd need someing with it's own controller, like CompactFlash or hard drives.
I've said it before, and I'll say it again: "RAID is not a backup technology." When your main disk gets hosed by a virus, a clumsy user, or a system crash, that corruption is coppied to the other disc at light speeds... So what's the point? Offline backups are what is needed. RAID provides a solution for hardware problems, which is important with critical systems, but if the hard drive in my home PC crashes after a year, as long as I can restore a recent backup, and only be down for a few hours, it's not really a problem.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
An article which simply jumps into a description of an esoteric subject can seem awkward and be difficult to understand, so journalists have long been taught strategies for lessening that initial impact. Many of these conventions don't play as well in the internet environment because a linking page has already told the reader what the article will really be about. This makes the lead seem like irrelevant wandering.
No, it is just a techical decision to do things that way... Hard drives are too bulky and expensive for small ammounts of storage, and tape drives are too expensive to have one tape per drive, not to mention the bulk.
In the real world, that isn't really the case. Your tapes are more likely to be damaged than a hard drive, mainly because the hard drive is extensively sheilded. Moving parts are only a problem after a long long run-time. If a hard drive's mechanical parts were working when you stored it, it will almost certainly work when you need to recover from it... Not to mention that hard drives CAN have everything but the platters swapped if you can find an identical device, or can be recovered manually by any simple data recovery center.
If you're talking about a live backup, you shouldn't be. One power surge could take out an entire RAID array. If you are talking about off-line, I have no idea why you bring up RAID.
Backup tapes are known to fail as well... That's why you make two of each, and send one off-site. Even if you aren't that stringent, your backup scheme should certainly have a LOT of redundancy in it, no matter what your media. I would certainly bet that hard drive failures are far more rare than tape failures.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant