{"id":88,"date":"2012-01-05T23:05:12","date_gmt":"2012-01-05T22:05:12","guid":{"rendered":"http:\/\/rady.707.cz\/web\/?p=88"},"modified":"2013-08-18T22:41:03","modified_gmt":"2013-08-18T21:41:03","slug":"pametova-media-soucasnost-az-blizka-budoucnost","status":"publish","type":"post","link":"https:\/\/www.deven.cz\/?p=88","title":{"rendered":"Pam\u011b\u0165ov\u00e1 media – sou\u010dasnost a\u017e bl\u00edzka budoucnost"},"content":{"rendered":"
\n
\"\"

harddisk<\/p><\/div><\/blockquote>\n

Historie HDD<\/h4>\n

13. z\u00e1\u0159\u00ed 1956 – \u00a0Po\u010d\u00edta\u010d IBM 305 RAMAC , kapacita jeho harddisku byla \u00a05 milion\u016f 7 bitov\u00fdch znak\u016f (asi 4,2 MB), jeho velikost byla 24 palc\u016f, disk se ot\u00e1\u010del rychlost\u00ed 78 RPM.<\/p>\n

Konstrukce Harddisk\u016f<\/h4>\n

Data jsou na disku ulo\u017eena pomoc\u00ed magnetick\u00e9ho z\u00e1znamu. Mag.\u00a0 z\u00e1znam se ukl\u00e1d\u00e1 na kovov\u00e9 nebo sklen\u011bn\u00e9 desky, naz\u00fdv\u00e1me je plotny. Pokryt\u00e9\u00a0 magneticky m\u011bkkou vrstvou. Bit ud\u00e1v\u00e1 hustotu dat na jednotku plochy ( b\/mm2<\/sup>, b\/cm2<\/sup>). Uvnit\u0159 disku najdeme v\u00edc jak jednu plotnu prakticky jich b\u00fdv\u00e1 1-5 ploten. Elektromotor ot\u00e1\u010d\u00ed v\u0159etenem a ten pot\u00e9 rotuje s\u00a0plotny. Standartn\u00ed rychlosti ot\u00e1\u010den\u00ed ploten jsou nap\u0159. 4\u00a0200 ot\/min, 5 400 ot\/min, 7 200 ot\/min a 10\u00a0000 ot\/min. O \u010dten\u00ed a z\u00e1pis dat se n\u00e1m postar\u00e1 \u010dtec\u00ed a zapisuj\u00edc\u00ed hlava.<\/p>\n

Z\u00a0po\u010d\u00e1tku byly pou\u017e\u00edv\u00e1ny magnetodynamick\u00e9 hlavy. Postupn\u011b byly nahrazeny krystalem. Hlava se povrchu plotny nedot\u00fdk\u00e1. Mezi plotnou a\u00a0 hlavou je jen p\u00e1r mikrometr\u016f. \u00a0Ka\u017ed\u00e1 plotna m\u00e1 dv\u011b strany, na kter\u00e9 lze zapsat data, proto tak\u00e9 je pot\u0159eba m\u00edt na ka\u017edou stranu plotny jednu hlavu. Ta m\u011bn\u00ed magnetickou polarizaci a t\u00edm tedy zapisuje data, kter\u00e1 nap\u0159\u00edklad od RAM pam\u011bti po vypnut\u00ed proudu nezmiz\u00ed. P\u0159ed samotn\u00fdm z\u00e1pisem \u010di \u010dten\u00edm mus\u00ed HDD nejprve poslat \u010dtec\u00ed hlavu na ur\u010denou pozici, utlumit rozkmit zp\u016fsoben\u00fd setrva\u010dnost\u00ed hlav a po\u010dkat na oto\u010den\u00ed plotny na m\u00edsto, od kter\u00e9ho se m\u00e1 \u010d\u00edst.<\/p>\n

Organizace hlav<\/h3>\n

Na povrchu pevn\u00e9ho disku jsou stopy (soust\u0159edn\u00e9 kru\u017enice), ka\u017ed\u00e1 stopa obsahuje pevn\u00fd anebo prom\u011bnn\u00fd po\u010det sektor\u016f z d\u016fvodu efektivn\u011bj\u0161\u00edho vyu\u017eit\u00ed povrchu. Povrch plotny je ve v\u011bt\u0161in\u011b p\u0159\u00edpad\u016f rozd\u011blen do n\u011bkolika z\u00f3n, ka\u017ed\u00e1 z\u00f3na m\u00e1 r\u016fzn\u00fd po\u010det sektor\u016f na stopu. \u010c\u00edm bl\u00ed\u017ee jsme ke st\u0159edu, t\u00edm je men\u0161\u00ed po\u010det sektor\u016f na stopu.<\/p>\n

Sektor<\/h4>\n

Sektor je nejmen\u0161\u00ed adresovatelnou jednotkou disku, m\u00e1 pevnou d\u00e9lku (doned\u00e1vna 512 byte na sektor, nyn\u00ed by se ji\u017e, po domluv\u011b v\u00fdrobc\u016f, m\u011bly vyr\u00e1b\u011bt disky s 4 KB na sektor).<\/p>\n

Cluster<\/h4>\n

Je aloka\u010dn\u00ed jednotka, logick\u00e1 jednotka, do kter\u00e9 se ukl\u00e1daj\u00ed data v souborov\u00e9m syst\u00e9mu. Slou\u010den\u00edm n\u011bkolika blok\u016f do v\u011bt\u0161\u00ed aloka\u010dn\u00ed jednotky se sni\u017euje komunikace PC s \u00falo\u017en\u00fdm za\u0159\u00edzen\u00edm, sni\u017euje se fragmentace a zvy\u0161uje se tak rychlost a efektivita p\u0159enosu dat.<\/p>\n

Rozhran\u00ed p\u0159ipojen\u00ed<\/h3>\n

Ata<\/h4>\n

ATA rozhran\u00ed m\u00e1 p\u0159enosnost 1Gb\/s (133MB\/s) na jeden ATA kabel lze p\u0159ipojit 2 za\u0159\u00edzen\u00ed, ale kles\u00e1 rychlost p\u0159enosu.<\/p>\n\n\n\n\n\n\n\n
P\u0159enosov\u00fd m\u00f3d<\/strong><\/td>\nStandart<\/strong><\/td>\nrychlost<\/strong><\/td>\n<\/tr>\n
Ultra DMA 33<\/strong><\/td>\nAPAPI-4<\/td>\n33 MB\/s<\/td>\n<\/tr>\n
Ultra DMA 66<\/strong><\/td>\nAPAPI-5<\/td>\n66 MB\/s<\/td>\n<\/tr>\n
Ultra DMA 100<\/strong><\/td>\nAPAPI-6<\/td>\n100 MB\/s<\/td>\n<\/tr>\n
Ultra DMA 133<\/strong><\/td>\nAPAPI-7<\/td>\n133 MB\/s<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Serial ATA ( SATA )<\/h4>\n

V\u00fdhody SATA jsou vy\u0161\u0161\u00ed rychlost inteligence \u0159adi\u010de umo\u017e\u0148uj\u00edc\u00ed optimalizaci datov\u00fdch p\u0159enos\u016f ncq. Mo\u017enost p\u0159ipojov\u00e1n\u00ed disk\u016f za chodu a men\u0161\u00ed rozm\u011bry kabel\u016f.<\/p>\n

Pole disk\u016f \u2013 RAID<\/h3>\n

Redundant Array of Inexpensive\/Independent Discs<\/p>\n

\"Pole

RAID 0<\/p><\/div>\n

v\u00edcen\u00e1sobn\u00e9 diskov\u00e9 pole lacin\u00fdch\/nez\u00e1visl\u00fdch disk\u016f<\/p>\n

RAID je metoda zabezpe\u010den\u00ed, kter\u00e1 m\u00e1 p\u0159edej\u00edt ztr\u00e1t\u011b dat. Nej\u010dast\u011bj\u0161\u00ed typy RAID\u016f jsou RAID\u00a00, RAID\u00a01, RAID\u00a05 \u010di RAID\u00a06.<\/p>\n

RAID 0<\/h4>\n

St\u0159\u00eddav\u011b ukl\u00e1d\u00e1 \u010d\u00e1sti dat na dva toto\u017en\u00e9 harddisky.\u00a0 P\u0159i poni\u010den\u00ed jednoho z\u00a0HDD tak ztr\u00e1c\u00edme data.<\/p>\n

 <\/p>\n

RAID 1 (zrcadlen\u00ed)<\/h4>\n

Je to jednoduch\u00e1, ale efektivn\u00ed ochrana proti ztr\u00e1t\u011b dat. Prov\u00e1d\u00ed se zrcadlen\u00ed obsahu prvn\u00edho disku na druh\u00fd. Z\u00e1pis m\u016f\u017ee b\u00fdt pomalej\u0161\u00ed, proto\u017ee se pracuje se dv\u011bma disky.<\/p>\n

Nev\u00fdhoda \u2013 pot\u0159eba dvojn\u00e1sobn\u00e1 kapacita HDD<\/p>\n

\"Pole

RAID 1 (zrcadlen\u00ed)<\/p><\/div>\n

 <\/p>\n

 <\/p>\n

 <\/p>\n

 <\/p>\n

SSD disky<\/h3>\n

Solid-state drive <\/strong><\/p>\n

Jedn\u00e1 se o \u00falo\u017ei\u0161t\u011b dat , kter\u00e9 pro ukl\u00e1d\u00e1n\u00ed pou\u017e\u00edv\u00e1 nevolatiln\u00ed flash pam\u011b\u0165. SSD disky byly konstruov\u00e1ny tak, aby nahradily HDD. To se jim moc dob\u0159e nepovedlo a to hlavn\u011b kv\u016fli velmi drah\u00e9 v\u00fdrob\u011b. Ale budoucnost pro n\u00e1s p\u0159ipravila mnohem lep\u0161\u00ed \u0159e\u0161en\u00ed.\u00a0 Nap\u0159\u00edklad harddisky\u00a0 s\u00a0n\u011bkolika stovky TB, kter\u00e9 zapisuj\u00ed data na DNA. Nebo Memrisor, kter\u00fd u\u017e klepe na dve\u0159e.<\/p>\n

\"Solid-state

SSD disky a jejich klady a z\u00e1pory<\/p><\/div>\n

Flash pam\u011b\u0165<\/h4>\n

Flash pam\u011b\u0165 je nevolatiln\u00ed (semipermanentn\u00ed) pam\u011bt, do kter\u00e9 se zapisuj\u00ed data elektronicky. Oproti HDD nem\u00e1 flash pam\u011b\u0165 pomalu \u017e\u00e1dnou latenci a to d\u00edky okam\u017eit\u00e9mu p\u0159\u00edstupu k\u00a0dan\u00fdm dat\u016fm velmi jednodu\u0161e \u0159e\u010deno pomoc\u00ed \u201esou\u0159adnic\u201c (nen\u00ed nutn\u00e9 ot\u00e1\u010det disk a vy\u010dkat na zm\u011bnu polohy hlavy). \u00a0Pam\u011b\u0165 je vnit\u0159n\u011b organizov\u00e1na po bloc\u00edch a na rozd\u00edl od pam\u011bt\u00ed typu EEPROM, lze programovat ka\u017ed\u00fd blok samostatn\u011b (obsah ostatn\u00edch blok\u016f je zachov\u00e1n). Pam\u011b\u0165 se pou\u017e\u00edv\u00e1 jako pam\u011b\u0165 typu ROM nap\u0159. pro ulo\u017een\u00ed firmware (nap\u0159. ve vestav\u011bn\u00fdch za\u0159\u00edzen\u00edch. Tuto pam\u011b\u0165 m\u016f\u017eeme pomalu do nekone\u010dna znovu naprogramovat (zapsat)<\/p>\n

Co n\u00e1m p\u0159in\u00e1\u0161\u00ed budoucnost?<\/h4>\n

Ka\u017ed\u00fd alespo\u0148 tro\u0161ku znal\u00fd elektroniky zn\u00e1 sou\u010d\u00e1stky jako odpor, kondenz\u00e1tor a c\u00edvku, ale zn\u00e1 n\u011bkdo memristory? Podle m\u011b m\u00e1 memristor mnohem lep\u0161\u00ed budoucnost ne\u017e nap\u0159\u00edklad SSD disky. Pro\u010d? To hned prozrad\u00edm, u\u017e jen proto, \u017ee jsi to nechci nechat pro sebe. S\u00e1m osobn\u011b t\u00e9to technologii dr\u017e\u00edm palce.<\/p>\n

Memristor<\/h2>\n
\"Memristor\"

Memristor<\/p><\/div>\n

\u00favod<\/h4>\n

Jak jsem p\u0159ed chv\u00edl\u00ed uvedl, jedn\u00e1 se o \u010dtvrtou elektronickou sou\u010d\u00e1stku, kter\u00e1 spat\u0159ila sv\u011btlo sv\u011bta roku 2008. Ale samotn\u00fd n\u00e1pad je star\u00fd ji\u017e 35 let, bylo to roku 1971. Dok\u00e1\u017ee zpracov\u00e1vat data stejn\u011b rychle jako RAM, nav\u00edc dok\u00e1\u017ee udr\u017eet data p\u0159i mnohem ni\u017e\u0161\u00edm nap\u011bt\u00ed a neztr\u00e1c\u00ed data ani p\u0159i odpojen\u00ed z\u00a0nap\u00e1jen\u00ed. S\u00e1m \u0161\u00e9f firmy HP uv\u00e1d\u00ed, \u017ee jednou memristory nahrad\u00ed pomal\u00e9 (oproti memristoru, nap\u0159. jsou 10X rychlej\u0161\u00ed ne\u017e flash) Flash a DRAM pam\u011bti. Samotn\u00fd n\u00e1zev Memristor vznikl ze slo\u017een\u00ed slov memory (pam\u011b\u0165) a rezistor (odpor). Pokud budeme cht\u00edt nap\u0159\u00edklad vyrobit 100 Flash pam\u011bti o velikosti 1GB tak za stejnou cenu n\u00e1klad\u016f vyrob\u00edme nejm\u00e9n\u011b 2x tolik pam\u011bt\u00ed ReRAM (\u201eresistive RAM\u201c, tedy MEMRISTOR).<\/p>\n

Princip vodivosti<\/h4>\n

Pam\u011b\u0165ov\u00e1 vrstva memristoru je vyrobena z\u00a0r\u016fzn\u00fdch metalick\u00fdch a nemetalick\u00fdch materi\u00e1l\u016f. V\u00fdzkum Riceovy univerzity uk\u00e1zal, \u017ee jako z\u00e1klad pam\u011b\u0165ov\u00e9 vrstvy memristoru m\u016f\u017ee slou\u017eit i oxid k\u0159emi\u010dit\u00fd. Fyzik\u00e1ln\u00ed vlastnosti k\u0159em\u00edku jsou zkoum\u00e1ny od 60\u00fdch let a v\u00fdzkum dok\u00e1zal, \u017ee je mo\u017en\u00e9 m\u011bnit odpor od nekone\u010dna t\u00e9m\u011b\u0159 k\u00a0nulov\u00e9 hranici. Pam\u011b\u0165ov\u00e9 bu\u0148ky z\u00a0oxidu k\u0159emi\u010dit\u00e9ho mohou m\u00edt rozm\u011bry pouze 5nm, zat\u00edmco flashov\u00e9 bu\u0148ky jen 20 nm – nar\u00e1\u017eej\u00ed na fyzik\u00e1ln\u00ed hranice. Pam\u011b\u0165ov\u00e1 bu\u0148ka memristoru vyu\u017e\u00edvaj\u00edc\u00ed oxid k\u0159emi\u010dit\u00fd,\u00a0 je aktivov\u00e1na b\u011bhem 100 nanosekund a p\u0159ed\u010d\u00ed flashov\u00e9 bu\u0148ky v\u00a0po\u010dtu<\/p>\n

\"Memristor\"<\/a>

Memristor<\/p><\/div>\n

z\u00e1pisov\u00fdch cykl\u016f.<\/p>\n

H-HDD hybridn\u00ed pevn\u00fd disk (nov\u00e1 generace)<\/h4>\n

Hybridn\u00ed pevn\u00e9 disky jsou vybaveny speci\u00e1ln\u00edm \u0159adi\u010dem, kter\u00fd zkop\u00edruje nejpou\u017e\u00edvan\u011bj\u0161\u00ed data do flash pam\u011bti a t\u00edm urychl\u00ed p\u0159\u00edstup k\u00a0\u010dasto pou\u017e\u00edvan\u00fdm \u00a0dat\u016fm. Seagate Momentus XT se od star\u00fdch H-HDD li\u0161\u00ed t\u00edm, \u017ee o v\u00fdb\u011br dat, kter\u00e1 budou zkop\u00edrov\u00e1ny na SSD, se star\u00e1 jeho \u0159adi\u010d a ne Windows. Notebookov\u00fd hybridn\u00ed disk p\u0159ekon\u00e1v\u00e1, co se t\u00fd\u010de rychlosti, i 3,5\u201c disky.<\/p>\n

Shrnut\u00ed<\/h4>\n

S\u00e1m osobn\u011b se velmi zaj\u00edm\u00e1m o technologick\u00e9 novinky – kdy\u017e jsem p\u0159em\u00fd\u0161lel, o \u010dem bych m\u011bl napsat, rozhodl jsem se popsat HDD a t\u00edmto jsem pouze shrnul jen to nejd\u016fle\u017eit\u011bj\u0161\u00ed, \u010di nejzaj\u00edmav\u011bj\u0161\u00ed ze sv\u011bta HDD a dal\u0161\u00edch pam\u011b\u0165ov\u00fdch m\u00e9di\u00ed. U\u017e jen kv\u016fli memristoru, jen\u017e m\u011b v\u00e1\u017en\u011b zaujal, no samoz\u0159ejm\u011b, \u017ee i daleko v\u00edce v\u011bc\u00ed, jako nap\u0159\u00edklad barevn\u00fd display, kter\u00fd funguje bez nap\u00e1jen\u00ed (mirasol) nebo p\u0159enos dat pomoc\u00ed laseru (Light Peak) \u010di dokonce HDD, kter\u00fd zapisuje data do DNA \u017eab\u00edch bun\u011bk, ale bohu\u017eel jsem zat\u00edm k\u00a0t\u011bmto technologick\u00fdm novink\u00e1m nem\u011bl dostate\u010dn\u00e9 informace.<\/p>\n","protected":false},"excerpt":{"rendered":"

Historie HDD 13. z\u00e1\u0159\u00ed 1956 – \u00a0Po\u010d\u00edta\u010d IBM 305 RAMAC , kapacita jeho harddisku byla \u00a05 milion\u016f 7 bitov\u00fdch znak\u016f (asi 4,2 MB), jeho velikost byla 24 palc\u016f, disk se ot\u00e1\u010del rychlost\u00ed 78 RPM. Konstrukce Harddisk\u016f Data jsou na disku ulo\u017eena pomoc\u00ed magnetick\u00e9ho z\u00e1znamu. Mag.\u00a0 z\u00e1znam se ukl\u00e1d\u00e1 na kovov\u00e9 …<\/p>\n","protected":false},"author":1,"featured_media":332,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0},"categories":[5,6],"tags":[11,16,9,8,7,13,12,10,15,14],"_links":{"self":[{"href":"https:\/\/www.deven.cz\/index.php?rest_route=\/wp\/v2\/posts\/88"}],"collection":[{"href":"https:\/\/www.deven.cz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.deven.cz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.deven.cz\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.deven.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=88"}],"version-history":[{"count":21,"href":"https:\/\/www.deven.cz\/index.php?rest_route=\/wp\/v2\/posts\/88\/revisions"}],"predecessor-version":[{"id":331,"href":"https:\/\/www.deven.cz\/index.php?rest_route=\/wp\/v2\/posts\/88\/revisions\/331"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.deven.cz\/index.php?rest_route=\/wp\/v2\/media\/332"}],"wp:attachment":[{"href":"https:\/\/www.deven.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=88"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.deven.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=88"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.deven.cz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=88"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}