{"id":5775,"date":"2016-08-18T18:16:56","date_gmt":"2016-08-18T11:16:56","guid":{"rendered":"http:\/\/ttud.com.vn\/?p=5775"},"modified":"2017-10-03T17:14:33","modified_gmt":"2017-10-03T10:14:33","slug":"bo-nho-doi-pha-pcm","status":"publish","type":"post","link":"https:\/\/casta.ttud.com.vn\/index.php\/bo-nho-doi-pha-pcm\/","title":{"rendered":"B\u1ed9 nh\u1edb \u0111\u1ed5i pha PCM"},"content":{"rendered":"

B\u1ed9 nh\u1edb \u0111\u1ed5i pha ( Phase Change Memory – PCM) l\u00e0 c\u00f4ng ngh\u1ec7 b\u1ed9 nh\u1edb kh\u00f4ng kh\u1ea3 bi\u1ebfn (non-volatile) h\u1ee9a h\u1eb9n s\u1ebd \u0111\u01b0\u1ee3c \u1ee9ng d\u1ee5ng tr\u00ean th\u1ebf h\u1ec7 \u1ed5 c\u1ee9ng SSD ti\u1ebfp theo. Tuy nhi\u00ean, kh\u00f4ng ch\u1ec9 \u1ed5 c\u1ee9ng m\u00e0 PCM ti\u1ec1m n\u0103ng c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c d\u00f9ng l\u00e0m b\u1ed9 nh\u1edb DRAM kh\u1ea3 bi\u1ebfn (volatile) \u0111\u1ec3 khai th\u00e1c \u01b0u \u0111i\u1ec3m v\u1ec1 t\u1ed1c \u0111\u1ed9 truy xu\u1ea5t c\u1ef1c cao c\u1ee7a n\u00f3. \u0110\u1ea1i h\u1ecdc Stanford \u0111\u00e3 ch\u1ee9ng minh r\u1eb1ng PCM c\u00f3 th\u1ec3 \u0111\u1ea1t t\u1ed1c \u0111\u1ed9 cao h\u01a1n g\u1ea5p ng\u00e0n l\u1ea7n so v\u1edbi DRAM th\u00f4ng th\u01b0\u1eddng.<\/strong><\/p>\n

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Tr\u01b0\u1edbc khi \u0111\u1ebfn v\u1edbi nghi\u00ean c\u1ee9u c\u1ee7a Stanford th\u00ec ch\u00fang ta c\u1ea7n ph\u1ea3i hi\u1ec3u r\u1eb1ng chip nh\u1edb silicon th\u00f4ng th\u01b0\u1eddng c\u00f3 2 d\u1ea1ng g\u1ed3m: b\u1ed9 nh\u1edb kh\u1ea3 bi\u1ebfn (volatile) nh\u01b0 RAM tr\u00ean m\u00e1y t\u00ednh v\u1edbi \u0111\u1eb7c t\u00ednh l\u00e0 d\u1eef li\u1ec7u s\u1ebd m\u1ea5t \u0111i khi m\u1ea5t \u0111i\u1ec7n (t\u1eaft m\u00e1y) v\u00e0 kh\u00f4ng kh\u1ea3 bi\u1ebfn (non-volatile) nh\u01b0 c\u00e1c lo\u1ea1i b\u1ed9 nh\u1edb flash (chip nh\u1edb tr\u00ean \u0111i\u1ec7n tho\u1ea1i hay \u1ed5 c\u1ee9ng SSD tr\u00ean m\u00e1y t\u00ednh) c\u00f3 th\u1ec3 l\u01b0u tr\u1eef d\u1eef li\u1ec7u ngay c\u1ea3 khi \u0111\u00e3 t\u1eaft m\u00e1y.<\/p>\n

B\u1ed9 nh\u1edb kh\u1ea3 bi\u1ebfn c\u00f3 t\u1ed1c \u0111\u1ed9 truy xu\u1ea5t cao h\u01a1n so v\u1edbi b\u1ed9 nh\u1edb kh\u00f4ng kh\u1ea3 bi\u1ebfn nh\u01b0ng b\u1ed9 nh\u1edb kh\u00f4ng kh\u1ea3 bi\u1ebfn l\u1ea1i c\u00f3 th\u1ec3 l\u01b0u tr\u1eef d\u1eef li\u1ec7u d\u00e0i l\u00e2u. \u0110\u00e2y c\u0169ng l\u00e0 l\u00fd do t\u1ea1i sao c\u00e1c c\u00f4ng ngh\u1ec7 b\u1ed9 nh\u1edb flash l\u1ea1i \u0111\u01b0\u1ee3c d\u00f9ng cho thi\u1ebft b\u1ecb l\u01b0u tr\u1eef trong khi \u0111\u00f3 RAM th\u00ec ho\u1ea1t \u0111\u1ed9ng ph\u1ed1i h\u1ee3p v\u1edbi CPU \u0111\u1ec3 l\u01b0u tr\u1eef d\u1eef li\u1ec7u t\u1ea1m th\u1eddi trong qu\u00e1 tr\u00ecnh t\u00ednh to\u00e1n b\u1edfi t\u1ed1c \u0111\u1ed9 c\u1ee7a n\u00f3 \u0111\u01b0\u1ee3c \u0111o b\u1eb1ng nano gi\u00e2y (10^-9 gi\u00e2y).<\/p>\n

PCM l\u00e0 m\u1ed9t c\u00f4ng ngh\u1ec7 b\u1ed9 nh\u1edb kh\u00f4ng kh\u1ea3 bi\u1ebfn r\u1ea5t \u0111\u1ed9c \u0111\u00e1o, \u0111\u01b0\u1ee3c ch\u1ebf t\u1ea1o b\u1eb1ng c\u00e1c v\u1eadt li\u1ec7u b\u00e1n d\u1eabn \u0111\u1eb7c bi\u1ec7t (ch\u1eb3ng h\u1ea1n nh\u01b0 thu\u1ef7 tinh chalcogenide) v\u00e0 \u0111\u01b0\u1ee3c ch\u00ednh nh\u1eefng k\u1ef9 s\u01b0 c\u1ee7a \u0111\u1ea1i h\u1ecdc Stanford nghi\u00ean c\u1ee9u t\u1eeb nh\u1eefng n\u0103m 60, 70 c\u1ee7a th\u1ebf k\u1ef7 tr\u01b0\u1edbc. C\u00f4ng ngh\u1ec7 b\u1ed9 nh\u1edb PCM c\u0169ng \u0111ang \u0111\u01b0\u1ee3c nhi\u1ec1u h\u00e3ng \u0111\u1ea7u t\u01b0 ph\u00e1t tri\u1ec3n nh\u01b0ng \u1ee9ng d\u1ee5ng ch\u1ee7 y\u1ebfu trong c\u00f4ng ngh\u1ec7 \u1ed5 c\u1ee9ng, ch\u1eb3ng h\u1ea1n nh\u01b0 IBM, HGST v\u00e0 th\u1eadm ch\u00ed Intel v\u1edbi c\u00f4ng ngh\u1ec7 b\u1ed9 nh\u1edb Optane\/3D Xpoint c\u0169ng \u0111\u01b0\u1ee3c cho l\u00e0 ph\u00e1t tri\u1ec3n d\u1ef1a tr\u00ean PCM.<\/p>\n

Th\u1ebf nh\u01b0ng c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u t\u1ea1i Stanford \u0111\u00e3 ch\u1ee9ng minh r\u1eb1ng PCM c\u00f3 th\u1ec3 mang nh\u1eefng \u01b0u \u0111i\u1ec3m l\u00ean c\u1ea3 2 lo\u1ea1i b\u1ed9 nh\u1edb, v\u1eeba c\u00f3 th\u1ec3 l\u01b0u tr\u1eef d\u1eef li\u1ec7u v\u0129nh c\u1eedu, v\u1eeba c\u00f3 th\u1ec3 mang l\u1ea1i t\u1ed1c \u0111\u1ed9 truy xu\u1ea5t nhanh h\u01a1n ng\u00e0n l\u1ea7n so v\u1edbi c\u00e1c lo\u1ea1i b\u1ed9 nh\u1edb hi\u1ec7n nay, ch\u01b0a k\u1ec3 l\u00e0 ti\u1ebft ki\u1ec7m \u0111i\u1ec7n n\u0103ng h\u01a1n.<\/p>\n

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Chip nh\u1edb silicon th\u00f4ng th\u01b0\u1eddng ho\u1ea1t \u0111\u1ed9ng theo c\u01a1 ch\u1ebf b\u1eadt v\u00e0 t\u1eaft c\u00e1c d\u00f2ng electron t\u01b0\u01a1ng \u1ee9ng v\u1edbi t\u00edn hi\u1ec7u 1 v\u00e0 0 k\u1ef9 thu\u1eadt s\u1ed1. C\u00e1c nh\u00e0 khoa h\u1ecdc v\u1eabn \u0111ang t\u00ecm ki\u1ebfm v\u1eadt li\u1ec7u m\u1edbi v\u00e0 quy tr\u00ecnh x\u1eed l\u00fd m\u1edbi sao cho ti\u1ebft ki\u1ec7m \u0111i\u1ec7n h\u01a1n v\u00e0 \u00edt chi\u1ebfm di\u1ec7n t\u00edch h\u01a1n so v\u1edbi silicon. PCM l\u00e0 m\u1ed9t trong nh\u1eefng gi\u1ea3i ph\u00e1p ti\u1ec1m n\u0103ng b\u1edfi n\u00f3 s\u1eed d\u1ee5ng c\u00e1c v\u1eadt li\u1ec7u s\u1edf h\u1eefu c\u1ea5u tr\u00fac nguy\u00ean t\u1eed linh ho\u1ea1t. PCM c\u00f3 2 tr\u1ea1ng th\u00e1i: kh\u00f4ng k\u1ebft tinh (amorphous) v\u1edbi tr\u1edf kh\u00e1ng cao v\u00e0 tr\u1ea1ng th\u00e1i k\u1ebft tinh (crystalline) v\u1edbi tr\u1edf kh\u00e1ng th\u1ea5p. \u1ede tr\u1ea1ng th\u00e1i kh\u00f4ng k\u1ebft tinh (hay h\u1ed7n lo\u1ea1n), c\u1ea5u tr\u00fac nguy\u00ean t\u1eed s\u1ebd ch\u1eb7n d\u00f2ng electron trong khi \u1edf tr\u1ea1ng th\u00e1i k\u1ebft tinh (hay tr\u1eadt t\u1ef1), c\u1ea5u tr\u00fac nguy\u00ean t\u1eed s\u1ebd cho d\u00f2ng electron di chuy\u1ec3n qua.<\/p>\n

Nguy\u00ean m\u1eabu PCIe SSD Onyx Moneta.\u200b<\/p>\n

S\u1edf d\u0129 v\u1eadt li\u1ec7u \u0111\u1ed5i pha \u0111\u01b0\u1ee3c xem l\u00e0 gi\u1ea3i ph\u00e1p thay th\u1ebf ti\u1ec1m n\u0103ng cho b\u1ed9 nh\u1edb silicon hi\u1ec7n t\u1ea1i b\u1edfi n\u00f3 c\u00f3 th\u1ec3 duy tr\u00ec b\u1ea5t c\u1ee9 tr\u1ea1ng th\u00e1i \u0111i\u1ec7n t\u00edch n\u00e0o th\u00edch nghi v\u1edbi c\u1ea5u tr\u00fac c\u1ee7a n\u00f3. M\u1ed9t khi nguy\u00ean t\u1eed v\u1eadt li\u1ec7u chuy\u1ec3n \u0111\u1ed5i qua l\u1ea1i gi\u1eefa 2 tr\u1ea1ng th\u00e1i \u0111\u1ec3 h\u00ecnh th\u00e0nh t\u00edn hi\u1ec7u 1 ho\u1eb7c 0 th\u00ec v\u1eadt li\u1ec7u c\u00f3 th\u1ec3 l\u01b0u tr\u1eef d\u1eef li\u1ec7u \u0111\u00f3 cho \u0111\u1ebfn khi m\u1ed9t ngu\u1ed3n n\u0103ng l\u01b0\u1ee3ng kh\u00e1c khi\u1ebfn n\u00f3 thay \u0111\u1ed5i. Kh\u1ea3 n\u0103ng l\u01b0u gi\u1eef d\u1eef li\u1ec7u n\u00e0y khi\u1ebfn b\u1ed9 nh\u1edb \u0111\u1ed5i pha kh\u00f4ng kh\u1ea3 bi\u1ebfn c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c d\u00f9ng nh\u01b0 b\u1ed9 nh\u1edb NAND flash tr\u00ean \u0111i\u1ec7n tho\u1ea1i hay \u1ed5 c\u1ee9ng SSD.<\/p>\n

Tuy nhi\u00ean, \u0111\u1ec3 s\u1eed d\u1ee5ng l\u00e0m b\u1ed9 nh\u1edb DRAM v\u1ed1n d\u0129 kh\u1ea3 bi\u1ebfn th\u00ec ngo\u00e0i kh\u1ea3 n\u0103ng l\u01b0u tr\u1eef d\u1eef li\u1ec7u, PCM c\u1ea7n ph\u1ea3i c\u00f3 t\u1ed1c \u0111\u1ed9 nhanh v\u00e0 ti\u00eau th\u1ee5 \u00edt \u0111i\u1ec7n n\u0103ng. Nh\u01b0\u1ee3c \u0111i\u1ec3m c\u1ed1 h\u1eefu c\u1ee7a b\u1ed9 nh\u1edb DRAM ch\u00ednh l\u00e0 kho\u1ea3ng tr\u1ed1ng b\u1ed9 nh\u1edb (memory gap hay memory wall) n\u00ean ch\u00fang ta c\u00f3 th\u1ec3 th\u1ea5y m\u1eb7c d\u00f9 xung nh\u1ecbp b\u1ed9 nh\u1edb DRAM \u0111\u00e3 kh\u00f4ng ng\u1eebng t\u0103ng trong su\u1ed1t 30 n\u0103m qua nh\u01b0ng kho\u1ea3ng th\u1eddi gian ph\u00e1t \u0111\u1ed9ng ch\u1ec9 th\u1ecb v\u00e0 ph\u1ea3n h\u1ed3i (hay \u0111\u1ed9 tr\u1ec5 latency) c\u1ee7a b\u1ed9 nh\u1edb v\u1eabn kh\u00f4ng \u0111\u01b0\u1ee3c c\u1ea3i thi\u1ec7n nhi\u1ec1u. Th\u00f4ng th\u01b0\u1eddng \u0111\u1ed9 tr\u1ec5 c\u1ee7a DRAM s\u1ebd t\u0103ng theo m\u1ed7i b\u01b0\u1edbc nh\u1ea3y v\u1ec1 xung nh\u1ecbp, ch\u1eb3ng h\u1ea1n nh\u01b0 chu k\u1ef3 truy xu\u1ea5t c\u1ee7a cell nh\u1edb (cycle time) theo t\u1ec9 l\u1ec7 nano gi\u00e2y c\u1ee7a DDR4-3200 s\u1ebd ngang v\u1edbi DDR3-1600 v\u00e0 t\u01b0\u01a1ng t\u1ef1 DDR3-1600 s\u1ebd ngang v\u1edbi DDR-400. V\u00e0 nh\u01b0\u1ee3c \u0111i\u1ec3m n\u00e0y c\u00f3 th\u1ec3 s\u1ebd \u0111\u01b0\u1ee3c kh\u1eafc ph\u1ee5c b\u1edfi PCM.<\/p>\n

Nh\u00f3m nghi\u00ean c\u1ee9u g\u1ed3m 19 th\u00e0nh vi\u00ean do ph\u00f3 gi\u00e1o s\u01b0 khoa h\u1ecdc v\u1eadt li\u1ec7u v\u00e0 khoa h\u1ecdc photon Aaron Lindenberg l\u00e3nh \u0111\u1ea1o \u0111\u00e3 t\u00ecm ra c\u00e1ch chuy\u1ec3n \u0111\u1ed5i nhanh gi\u1eefa 2 tr\u1ea1ng th\u00e1i kh\u00f4ng k\u1ebft tinh v\u00e0 k\u1ebft tinh c\u1ee7a v\u1eadt li\u1ec7u t\u01b0\u01a1ng \u1ee9ng v\u1edbi chuy\u1ec3n t\u1eeb 0 sang 1 v\u00e0 1 tr\u1edf v\u1ec1 0 b\u1eb1ng c\u00e1ch \u00e1p d\u1ee5ng c\u00e1c xung \u0111i\u1ec7n ho\u1eb7c quang.<\/p>\n

H\u1ecd \u0111\u1eb7t m\u1ed9t m\u1eabu v\u1eadt li\u1ec7u k\u1ebft tinh v\u00e0o m\u1ed9t \u0111i\u1ec7n tr\u01b0\u1eddng c\u00f3 s\u1ee9c m\u1ea1nh t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi m\u1ed9t tia s\u00e9t. D\u1ef1a tr\u00ean m\u1ed9t thi\u1ebft b\u1ecb \u0111o, c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u \u0111\u00e3 \u0111o \u0111\u01b0\u1ee3c c\u1ea5u tr\u00fac nguy\u00ean t\u1eed c\u1ee7a v\u1eadt li\u1ec7u \u0111\u1ed5i tr\u1ea1ng th\u00e1i t\u1eeb k\u1ebft tinh (0) sang k\u1ebft tinh (1) trong ch\u01b0a \u0111\u1ea7y 1 pico gi\u00e2y (10^-12 gi\u00e2y). \u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a PCM c\u00f3 th\u1ec3 l\u01b0u tr\u1eef d\u1eef li\u1ec7u nhanh h\u01a1n g\u1ea5p nhi\u1ec1u l\u1ea7n so v\u1edbi RAM l\u00e0m b\u1eb1ng silicon \u0111\u1ed1i v\u1edbi nh\u1eefng t\u00e1c v\u1ee5 \u0111\u00f2i h\u1ecfi b\u1ed9 nh\u1edb v\u00e0 vi x\u1eed l\u00fd ph\u1ea3i ho\u1ea1t \u0111\u1ed9ng v\u1edbi t\u1ed1c \u0111\u1ed9 cao nh\u01b0 nhau. Nh\u01b0 v\u1eady c\u00f3 th\u1ec3 n\u00f3i PCM s\u1ebd lo\u1ea1i b\u1ecf kho\u1ea3ng c\u00e1ch v\u1ec1 \u0111\u1ed9 tr\u1ec5 gi\u1eefa b\u1ed9 nh\u1edb RAM v\u00e0 CPU.<\/p>\n

Tuy nhi\u00ean, v\u1eabn c\u00f2n nhi\u1ec1u tr\u1edf ng\u1ea1i tr\u00ean b\u01b0\u1edbc \u0111\u01b0\u1eddng \u1ee9ng d\u1ee5ng c\u00f4ng ngh\u1ec7 PCM v\u00e0o b\u1ed9 nh\u1edb DRAM b\u1edfi l\u1ebd nh\u1eefng xung \u0111i\u1ec7n n\u0103ng l\u01b0\u1ee3ng l\u1edbn v\u1eabn ch\u01b0a th\u1ec3 \u0111\u01b0\u1ee3c t\u1ea1o ra tr\u00ean m\u1ea1ch PCB v\u00e0 t\u00edn hi\u1ec7u kh\u00f3 c\u00f3 th\u1ec3 truy\u1ec1n \u0111i th\u00f4ng qua nh\u1eefng m\u1ea1ch in b\u1eb1ng \u0111\u1ed3ng tr\u00ean thi\u1ebft k\u1ebf bo m\u1ea1ch hi\u1ec7n \u0111\u1ea1i. Nh\u1eefng g\u00ec ch\u00fang ta \u0111\u01b0\u1ee3c bi\u1ebft hi\u1ec7n t\u1ea1i l\u00e0 PCM c\u00f3 th\u1ec3 chuy\u1ec3n \u0111\u1ed5i tr\u1ea1ng th\u00e1i r\u1ea5t nhanh. Kh\u1ea3 n\u0103ng ho\u1ea1t \u0111\u1ed9ng \u1edf t\u1ec9 l\u1ec7 pico gi\u00e2y kh\u00f4ng \u0111\u1ea3m b\u1ea3o r\u1eb1ng c\u00f4ng ngh\u1ec7 n\u00e0y s\u1ebd thay th\u1ebf DRAM nh\u01b0ng n\u00f3 ch\u1ee9ng minh r\u1eb1ng PCM c\u00f3 ti\u1ec1m n\u0103ng ho\u1ea1t \u0111\u1ed9ng \u1edf c\u00e1c t\u1ea7n s\u1ed1 m\u00e0 DRAM kh\u00f4ng th\u1ec3 n\u00e0o ch\u1ea1m t\u1edbi.<\/p>\n

Theo: Stanford\u200b<\/em><\/p>\n

Ngu\u1ed3n tinhte.vn<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

B\u1ed9 nh\u1edb \u0111\u1ed5i pha ( Phase Change Memory – PCM) l\u00e0 c\u00f4ng ngh\u1ec7 b\u1ed9 nh\u1edb kh\u00f4ng kh\u1ea3 bi\u1ebfn (non-volatile) h\u1ee9a h\u1eb9n s\u1ebd \u0111\u01b0\u1ee3c \u1ee9ng d\u1ee5ng tr\u00ean th\u1ebf h\u1ec7 \u1ed5 c\u1ee9ng SSD ti\u1ebfp theo. Tuy nhi\u00ean, kh\u00f4ng ch\u1ec9 \u1ed5 c\u1ee9ng m\u00e0 PCM ti\u1ec1m n\u0103ng c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c d\u00f9ng l\u00e0m b\u1ed9 nh\u1edb DRAM kh\u1ea3 bi\u1ebfn (volatile) \u0111\u1ec3 […]<\/p>\n","protected":false},"author":17,"featured_media":7202,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[],"class_list":["post-5775","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tin-tuc"],"_links":{"self":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/5775","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/users\/17"}],"replies":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/comments?post=5775"}],"version-history":[{"count":4,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/5775\/revisions"}],"predecessor-version":[{"id":7204,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/5775\/revisions\/7204"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/media\/7202"}],"wp:attachment":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/media?parent=5775"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/categories?post=5775"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/tags?post=5775"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}