Mene ne cache memory

Ba duk kwamfuta masu san cewa irin wannan cache, ko da yake shi ne rayayye amfani da cikakken duk masana'antun, duka biyu sarrafawa da kuma shirye-shirye. Wasu masu amfani sun kawai kwanan nan ya fara ci gaba da wani sirri kwamfuta, wani lokacin a kan Tattaunawa a Global Network koka jinkirin yi na lantarki mataimakansa. Alal misali, idan 5 seconds wuce tsakanin farkon na tag ofishin shirye-shirye da kuma zargin da windows, to, shi yana dauke su wani gagarumin lokaci. Ko jihohin da suke da 10-15 seconds ne dole kora da tsarin aiki daga rumbunka ga Magnetic da akussa - vata lokaci. Abin mamaki: kawai dozin shekaru da suka wuce, da ƙaddamar da shirin zai iya daukar har kusan rabin minti daya, da kuma aka dauke da sauri. Abu daya ne bayyananne - ƙara kwamfuta yi muhimmanci da kuma wannan ba karshe rawa da cache processor.

Kamar yadda amfani da kwamfuta hardware memory kayayyaki bisa DRAM fasahar (tsauri memory bazuwar damar). Features na wannan fasahar a low cost, high AMINCI da ... mun gwada low gudun. DRAM amfani da goma da suka wuce, ko da yake har yanzu a hankali ta gyare-gyare. Idan a lokacin da damar yin amfani da memory Kwayoyin an jinkirta game da 200 nanoseconds, sa'an nan yanzu wannan darajar ta shawo kan shãmaki 20 ns. Zai ze - gudun kasance kawai dama! Duk da haka, a cikin layi daya tare da kyautata na DRAM kuma ya karu da damar da processor bas, don haka da sauran rabo ya canza ba haka ba kamar yadda iya. A nan mun zo da tambaya na abin da cache. Ta yaya zan iya kara wasan kwaikwayon na subsystem Computer Memory? Amsar ne bayyananne - shi ne mai yiwuwa a sauya rabu amfani DRAM wani abu mafi m. Amma da m Intel kwarewa da tsada sanduna Rambus nuna cewa maye kamata ba muhimmanci ƙara jimlar kudin.

Ba tare da wannan hanin, ba wanda zai taba yi zaton cewa wannan cache, saboda a irin wannan inji ba zai zama yawa batu. Isa ya maye gurbin mafi m DRAM SRAM (canzawa bazuwar memory damar) da kuma matsalar za a warware. Amma wannan zai haifar da gagarumin karuwa a cost. Saboda haka ina samarwa a yi jayayya version nasara cewa ya shafi daga lokacin na farko 80286-gudun memory tubalan aka shirya don kara wasan kwaikwayon na tsarin tsakanin gwada da m memory kayayyaki da kuma high-gudun processor. Dangi da adadin DRAM Kwayoyin ne musamman bai isa a kula adadin, jere daga 8 kbps (matakin L1) har zuwa dubun megabytes (L3 matakin). Musamman mai kula wuce ta wata guda biyu-directional data rafi da kofe na su a cikin azumi memory. A na gaba request da CPU da DRAM mai kula cak ko akwai wani "bar" dama DATA, kuma idan aka same su, da watsa processor ne kawai a cache. Kamar yadda za a iya gani, da aiki da ka'ida ne quite sauki. Matsalolin bayyana a cikin hanyoyin aiwatar: developers yi hukunci da abin da irin bayanan ne Kwafin, da yadda za a sabunta su, da yadda za a inganta aikin yadda ya dace, da dai sauransu Amma wannan shi ne wata babbar topic, don haka mafi daga gare ta za a iya samu a cikin na musamman kafofin ..

Saboda haka, amsar wannan tambaya na abin da wani cache memory, za a iya tsara kamar haka: da cache ne buffer a cikin abin da mai kula rubuta / karanta data, kara yi na memory subsystem.

Kuma game da cibiyar sadarwa da aikace-aikacen da cewa shi ne cache? The browser mai amfani a lokacin da na duba shafukan a yanar-gizo yin amfani da wannan bayani. Lokacin da na farko bude wani na abubuwa, da dama shafukan (image data) adana a babban fayil a kan Disc, kuma ga m accesses wannan data da aka ba wa lodi daga m yanar gizo, da kuma aka saka a cikin fayil, da kara hawan igiyar ruwa gudu. Hanzari ne musamman m at low gudu na Internet.