Mune indasitiri yekomputa, takagara nePCIe seyakajairwa kwenguva yakareba. Iyo inoshandiswa kuwedzera chero mamwe maficha kune ino sisitimu: girafu, chengetedzo, USB madoko, kumwe kuchengetedza, network, kuwedzera-mumakadhi, kuchengetedza, makadhi ezwi, Wi-Fi, oh ndataura zvekuchengetedza? Zvakanaka chinhu chimwe chatisina kukwanisa kuisa mukati mePCIe slot iDRAM - Handireve kuti DRAM sedhizaivhi yekuchengetera, asi ndangariro iyo inowedzerwa kuhurongwa seunogona kushandiswa DRAM. Kudzoka mu2019 imwe nyowani yeCXL yakaunzwa, iyo inoshandisa iyo PCIe 5.0 chinongedzo seicho chinoonekwa chimiro. Chikamu cheiyo standard ndeye CXL.memory - kugona kuwedzera DRAM muchirongwa kuburikidza neCXL / PCIe slot. Nhasi Samsung iri kufumura yekutanga DRAM module yakanyatsogadzirirwa nenzira iyi.
CXL: Zororo
The yekutanga CXL yakajairwa yakatanga sepurojekiti yekutsvagisa mukati meIntel kugadzira chinongedzo chinogona kutsigira zvinowedzera simba, IO, cache, uye ndangariro. Iyo yakazotenderera mumubatanidzwa wayo, iine nhengo dzinopfuura makumi mashanu, uye rutsigiro kubva kune vakakosha vatambi muindasitiri: Intel, AMD, Arm, IBM, Broadcom, Marvell, NVIDIA, Samsung, SK Hynix, WD, nevamwe. Iyo yazvino standard ndeye CXL 50, yakagadziriswa munaNovember 2.0.
Iyo CXL 1.1 yakajairwa inovhara matatu seti eiyo epamukati, inozivikanwa seCXL.io, CXL.memory uye CXL.cache. Izvi zvinobvumira kudzora kwakadzika pamusoro pemidziyo yakabatana, pamwe nekuwedzera kune izvo zvinogoneka. ICXL Consortium inoona nharaunda nhatu huru dzeichi:
Rudzi rwekutanga ndeye cache / accelerator, senge injini yekuburitsa kana SmartNIC (smart network controller). Iine CXL.io uye CXL.cache intrinsics, izvi zvaizobvumidza iyo network mutongi kuronga data irikupinda, kuriongorora, uye kusefa izvo zvinodikanwa zvakanangisa mukati meiyo huru processor yekumusoro.
Rudzi rwechipiri ndeyekuwedzera chiyeuchidzo chiyeuchidzo, uye kunanga kwakananga kune iyo HBM pane iyo yekumhanyisa kubva kune processor (pamwe nekusvika kuDRAM kubva kunowedzera). Pfungwa iyi ndeyekunyepedzera-kusarongeka dhizaini dhizaini inobvumira nyore asi akaomarara komputa yekugadzirisa.
Rudzi rwechitatu pamwe ndirwo rwatinonyanya kufarira nhasi: memory buffers. Uchishandisa CXL.memory, memory memory buffer inogona kuiswa pamusoro peCXL chinongedzo uye ndangariro dzakabatanidzwa dzinogona kubatanidzwa zvakananga neiyo system memory. Izvi zvinobvumidza chero yakawedzera memory bandwidth, kana yakawedzera memory memory, kune odhiyo yezviuru zvegigabytes.
CXL 2.0 zvakare inosvitsa CXL. Chengetedzo, rutsigiro rwekuramba uchiyeuka, uye nekuchinja kugona.
Izvo zvinofanirwa kucherechedzwa kuti CXL iri kushandisa imwechete magetsi magetsi sePCIe. Izvi zvinoreva kuti chero mudziyo weCXL unenge uine zvinoita senge PCIe inobatanidza muviri. Kupfuura izvozvo, CXL inoshandisa PCIe mukutanga kwayo, saka parizvino chero chinotsigira CXL inofanirwa kutsigirawo PCIe-to-PCIe chinongedzo, ichiita chero mutongi weCXL zvakare mutungamiriri wePCIe nekutadza.
Mumwe wemibvunzo yakajairika yandakaona ndeyekuti chii chingaitika kana CXL-chete CPU ikagadzirwa? Nekuti CXL nePCI zvakabatana, CPU haigone kuve CXL-chete, yaifanirwa kutsigira PCIe kubatana zvakare. Izvo zviri kutaurwa, kubva kune rimwe divi: kana isu tichiona CXL-yakavakirwa magiraidhi makadhi semuenzaniso, ivo vanofanirwawo kumbotanga kutanga pamusoro pePCIe, zvisinei zvizere nzira dzekushanda dzinogona kunge dzisingakwanisike kana CXL isina kutangwa.
Intel yakagadzirirwa kuunza CXL 1.1 pamusoro pePCIe 5.0 pamwe neSapphire Rapids processors. Microchip yazivisa PCIe 5.0 uye CXL-based retimers emamaboard trace ekuwedzera. Samsung nhasi chiziviso chechitatu chemidziyo inotsigirwa neCXL. IBM ine tekinoroji yakafanana inonzi OMI (OpenCAPI Memory Interface), zvisinei izvo hazvina kuona kutorwa kwakawanda kunze kweavo maBM processor.
Samsung's CXL Chiyeuchidzo Module
Ma processor epanhasi anovimba neanodzora ndangariro kune akabatanidza DRAM kuwana. Iyo yekumusoro mutsara x86 processor ine masere masere eDDR4, nepo akati wandei anowedzera akadzika munzira yeHBM. Chimwe chezvinhu zvinodzikamisa mukukwirisa memory bandwidth ndiyo nhamba yevanodzora, iyo inogona zvakare kudzikamisa kugona, uye pamusoro peiyo ndangariro inoda kusimbiswa uye kudzidziswa kushanda nehurongwa. Mazhinji masisitimu haana kuvakwa kungo wedzera kana kubvisa ndangariro nenzira imwecheteyo yaungaite neyekuchengetedza mudziyo.
Pinda CXL, uye kugona kuwedzera ndangariro senge mudziyo wekuchengetedza. Kufumurwa kweSamsung nhasi ndeyeCXL-yakasungirirwa module yakazadzwa kune iyo max neDDR5. Iyo inoshandisa yakazara PCIe 5.0 x16 chinongedzo, ichibvumidza iyo yetioretical bidirectional 32 GT / s, asi iine yakawanda TB yekurangarira kuseri kweye buffer controller. Nenzira imwecheteyo makambani akaita seSmall pack NAND muU.2-saizi fomu chinhu, ine kutonhora kwakaringana, Samsung inoita zvakafanana pano asi neDRAM.
Iyo DRAM ichiri ndangariro isingachinji, uye data inorasika kana simba rikarasika. (Ini ndinokahadzika kuti inopisa swappable kana, asi weirder zvinhu zvaitika). Inoramba ichiyeuka inogona kushandiswa, asi chete neCXL 2.0. Samsung haina kutaura kana mudziyo wavo unotsigira CXL 2.0, asi inofanirwa kunge iri CXL 1.1 sezvavanotaura kuti parizvino iri kuedzwa neIntel's Sapphire Rapids chikuva.
Izvo zvinofanirwa kucherechedzwa kuti yazvino DRAM slot inowanzo ratidzirwa yakakwira ye ~ 18W. Iwo chete ma module mune iro simba rewindo ndeye Intel's Optane DCPMM, asi 256 GB DDR4 module ichave mune iyo ~ 10 + W renji. Kune 2 TB yekuwedzera-muCXL module yakadai, ndinofungidzira kuti tiri kutarisa kwakatenderedza 70-80 W, uye nekudaro kuwedzera huwandu uhu hweDRAM kuburikidza neCXL interface ingangoda kutonhodza kutonhodza pamwe neheatsink hombe iyo inopa funga.
Samsung haipe chero ruzivo nezve module yavari kuburitsa, kunze kwekunge iri CXL yakavakirwa uye iine DDR5 mairi. Kwete izvozvo chete, asi iwo 'mapikicha' akapihwa anotaridzika zvakanyanya sekushandurwa, saka zvakaoma kutaura kana vaine yekushongedza unit inowanikwa yekutora mifananidzo, kana kana paine kungori anoshanda anoshanda mune yekuunza-kumusoro lab kune imwe nzvimbo iyo yakave yakasimbiswa pa hurongwa. Kwidziridzo: Samsung yakasimbisa aya mapfuti epamoyo, kwete kupa.
Sechikamu chekuzivisa Samsung yakataura AMD neIntel, zvichiratidza kuti ndevapi vavanoshanda navo zvakanyanya, uye izvo zvavainazvo nhasi zviri kuvimbiswa pamaseva eIntel anotevera-gen. Intel anotevera-gen maseva, Sapphire Rapids, anofanirwa kuvhurwa pakupera kwegore, zvinoenderana neAurora supercomputing kontrakiti yakagadzirirwa kutanga kutumirwa nekupera kwegore.