If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Replace magnetic with optical
Hi:
Why do hard disc drives use magnetic discs? Since non-volatile flash RAM chips are not yet feasible for HDD- substitution, why not replace the magnetic platters with optical ones that use 400 nm lasers to write, read, erase, and re-write data? Optical platters using 400 nm lasers would surely have advantages over magnetic platters. More data per area and less vulnerability to environmental magnetic disruptions -- to name a few. I say dump all magnetic discs and replace them with the optical equivalent. Use 400 nm lasers because 400 nm is the sweet spot between shortest wavelength and non-ionizing radiation. Shorter wavelengths require less size to write/read data. Too short and you increase your risk of cancer. So use 400 nm and dump those useless magnetic discs. Red lasers -- used by CDs -- are horrible because they require so much space on the disk to write data. Green lasers -- used by DVDs -- are a tad better. Blu-ray -- at 405 nm -- is almost at the best wavelength but not quite! Regards, Radium |
#2
|
|||
|
|||
Replace magnetic with optical
"Radium" wrote in
oups.com: Yum, looks likr I get first bite. Why do hard disc drives use magnetic discs? Since non-volatile flash RAM chips are not yet feasible for HDD- substitution, why not replace the magnetic platters with optical ones that use 400 nm lasers to write, read, erase, and re-write data? Possibly because decades ago, there were no blue laser diodes? Optical platters using 400 nm lasers would surely have advantages over magnetic platters. More data per area and less vulnerability to environmental magnetic disruptions -- to name a few. It's been tried, but I'll not try to pr-empt the words of those who know far more history than I do. As to volume, a single platter of a hard disk can hold a few hundred GB. There is an optical disk being developed that is said to have more, but I don't think it's on sale yet. Current blue diode disks don't hold anything like this much. Multiply by four or so, per layer, but not by a hundred. I say dump all magnetic discs and replace them with the optical equivalent. Use 400 nm lasers because 400 nm is the sweet spot between shortest wavelength and non-ionizing radiation. Shorter wavelengths require less size to write/read data. Too short and you increase your risk of cancer. So use 400 nm and dump those useless magnetic discs. Less soze, no, as I said. Less time? Definitely not. And if you spun an optical disk as fast as a hard disk, the laser would have to be extremely strong to write to the surface it as it passes by so rapidly. Red lasers -- used by CDs -- are horrible because they require so much space on the disk to write data. Green lasers -- used by DVDs -- are a tad better. Blu-ray -- at 405 nm -- is almost at the best wavelength but not quite! If you can find a green laser in a DVD, and prove you found it, grab that time machine with both hands and patent it before anyone else gets there first. |
#3
|
|||
|
|||
Replace magnetic with optical
On 3 Apr 2007 13:16:05 -0700, "Radium"
wrote: Hi: Why do hard disc drives use magnetic discs? High data density and speed, leveraging mature technology incrementally updated for reasonable cost effectiveness. Since non-volatile flash RAM chips are not yet feasible for HDD- substitution, They are, but it'd cost a lot. Too much mostly because Bill Gates & Co. let windows become so bloated it now needs Gigabytes of space, but the other software manufacturers are to blame as well. why not replace the magnetic platters with optical ones that use 400 nm lasers to write, read, erase, and re-write data? Is what you have in mind as cheap and fast? Usually optical is not. Optical platters using 400 nm lasers would surely have advantages over magnetic platters. More data per area and less vulnerability to environmental magnetic disruptions -- to name a few. What makes you think a "magnetic disruption" is a significant problem? What makes you think there is any less vulnerability at all? A hard drive has a GREAT deal of mechanical movement, other devices meant for lesser read and write cycles might be viable if cheap enough, small enough, and fast enough, but if only more expensive, no smaller and no faster, the one thing you assume is not a clear victory. I say dump all magnetic discs and replace them with the optical equivalent. Use 400 nm lasers because 400 nm is the sweet spot between shortest wavelength and non-ionizing radiation. Shorter wavelengths require less size to write/read data. Too short and you increase your risk of cancer. So use 400 nm and dump those useless magnetic discs. You seem unable to use current technology if you find it such a problem. Thus, if we introduced this tech you want, you would be as likely to just find it a problem and pretend you have an advanced insight on some other thing that isn't here yet either, only a hypothetical device which in practice may also have drawbacks. Red lasers -- used by CDs -- are horrible because they require so much space on the disk to write data. Green lasers -- used by DVDs -- are a tad better. Blu-ray -- at 405 nm -- is almost at the best wavelength but not quite! Forget ideals and focus on real needs. The market doesn't really need a concept drive they need something proven through years of testing. That at an attractive price point. Eventually there will be more optical alternatives but it would be foolish to "dump all magnetic discs" before the replacement technology is ready. Your ideas are akin to "cars suck, dump all cars and use space ships", but wordier. |
#4
|
|||
|
|||
Replace magnetic with optical
(snipped everything)
Optical drives are way too slow, way too low capacity, and not as reliable as hard drives. Flash is too expensive and has write endurance problems. Write a block a couple hundred thousand times (like a directory block) and it dies. John |
#5
|
|||
|
|||
Replace magnetic with optical
On Apr 3, 5:19 pm, John Larkin
wrote: Optical drives are way too slow, way too low capacity, and not as reliable as hard drives. So a magnetic disc will have a higher capacity and speed than an optical disc of the same size? Flash is too expensive and has write endurance problems. Write a block a couple hundred thousand times (like a directory block) and it dies. Is this due to overheating of circuits? |
#6
|
|||
|
|||
Replace magnetic with optical
Radium wrote:
.... snip ... Optical platters using 400 nm lasers would surely have advantages over magnetic platters. More data per area and less vulnerability to environmental magnetic disruptions -- to name a few. Not so. To prove it to yourself, go out and buy a 200 odd gig hard drive. Rip it open, and discard all parts other than the rotatable disk(s) itself. Now compare its volume with that of a DVD disk, which holds maybe 8 gig. -- Chuck F (cbfalconer at maineline dot net) Available for consulting/temporary embedded and systems. http:/X-Mozilla-Status: 0009et -- Posted via a free Usenet account from http://www.teranews.com |
#7
|
|||
|
|||
Replace magnetic with optical
Radium wrote:
Hi: Why do hard disc drives use magnetic discs? Since non-volatile flash RAM chips are not yet feasible for HDD- substitution, why not replace the magnetic platters with optical ones that use 400 nm lasers to write, read, erase, and re-write data? Optical platters using 400 nm lasers would surely have advantages over magnetic platters. More data per area and less vulnerability to environmental magnetic disruptions -- to name a few. I say dump all magnetic discs and replace them with the optical equivalent. Use 400 nm lasers because 400 nm is the sweet spot between shortest wavelength and non-ionizing radiation. Shorter wavelengths require less size to write/read data. Too short and you increase your risk of cancer. So use 400 nm and dump those useless magnetic discs. Red lasers -- used by CDs -- are horrible because they require so much space on the disk to write data. Green lasers -- used by DVDs -- are a tad better. Blu-ray -- at 405 nm -- is almost at the best wavelength but not quite! Regards, Radium You don't need permission from me -- or from Bill Gates -- to do so. You may need to hack the OS a bit to boot/run from the DVD of your choice, which is easier with a *NIX than a WinWhatever. Then boot from and run from that DVD, and report back on how fast it is, relative to the normal HD you will then be wanting back. Oh, and make sure you use a PC with limited RAM, to feel the effects of swapping to your DVD. -- Cheers, Bob |
#8
|
|||
|
|||
Replace magnetic with optical
CBFalconer writes:
Radium wrote: ... snip ... Optical platters using 400 nm lasers would surely have advantages over magnetic platters. More data per area and less vulnerability to environmental magnetic disruptions -- to name a few. Not so. To prove it to yourself, go out and buy a 200 odd gig hard drive. Rip it open, and discard all parts other than the rotatable disk(s) itself. Now compare its volume with that of a DVD disk, which holds maybe 8 gig. Not quite a fair comparison. A double sided double layer DVD can hold around 20 GB. A similar blu-ray (405 nm) disc could hold 5 to 10 times that. A holographic memory of the same volume could hold much more. And when is the last time your harddrive was affected by an "environmental magnetic disruption" short of an EMP from a nuclear blast? --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs. |
#9
|
|||
|
|||
Replace magnetic with optical
I wonder why no one has commented on him (original topic starter) that he
saying they use green lasers for dvd. "Bob Willard" wrote in . .. Radium wrote: Hi: Why do hard disc drives use magnetic discs? Since non-volatile flash RAM chips are not yet feasible for HDD- substitution, why not replace the magnetic platters with optical ones that use 400 nm lasers to write, read, erase, and re-write data? Optical platters using 400 nm lasers would surely have advantages over magnetic platters. More data per area and less vulnerability to environmental magnetic disruptions -- to name a few. I say dump all magnetic discs and replace them with the optical equivalent. Use 400 nm lasers because 400 nm is the sweet spot between shortest wavelength and non-ionizing radiation. Shorter wavelengths require less size to write/read data. Too short and you increase your risk of cancer. So use 400 nm and dump those useless magnetic discs. Red lasers -- used by CDs -- are horrible because they require so much space on the disk to write data. Green lasers -- used by DVDs -- are a tad better. Blu-ray -- at 405 nm -- is almost at the best wavelength but not quite! Regards, Radium You don't need permission from me -- or from Bill Gates -- to do so. You may need to hack the OS a bit to boot/run from the DVD of your choice, which is easier with a *NIX than a WinWhatever. Then boot from and run from that DVD, and report back on how fast it is, relative to the normal HD you will then be wanting back. Oh, and make sure you use a PC with limited RAM, to feel the effects of swapping to your DVD. -- Cheers, Bob |
#10
|
|||
|
|||
Replace magnetic with optical
"Sam Goldwasser" wrote in message ... Not quite a fair comparison. A double sided double layer DVD can hold around 20 GB. A similar blu-ray (405 nm) disc could hold 5 to 10 times that. A holographic memory of the same volume could hold much more. Now you've done it, Sam...Radium will be after us now re his latest and greatest fantasy, the holographic-storage laptop. And it will be entirely YOUR fault.... Bob M. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Replace magnetic with opticals | Radium[_2_] | Storage (alternative) | 1 | April 9th 07 08:36 PM |
printing on magnetic sheets | CNN_news | Printers | 4 | February 8th 06 05:47 PM |
Magnetic Card Reader | Thomas Zimmermann | General | 1 | September 1st 05 07:44 PM |
Magnetic Card Reader | Thomas Zimmermann | General | 0 | August 26th 05 12:28 PM |
Magnetic Ink? | Clark Wilhelm Griswold, Jr. | Printers | 12 | June 27th 03 08:37 PM |