QSFP28 vs QSFP-DD: Phau Ntawv Qhia Ua Haujlwm tiav rau xyoo 2026

Saib, yog tias koj tab tom spec'ing tawm lub chaw khaws ntaub ntawv tshiab lossis npaj koj tus txha nraub qaum tom ntej- nplooj tsim tawm, tej zaum koj tau ntaus cov lus nug no: lo nrog sim-thiab- tseeb 100G QSFP28, lossis ua kom dhia mus rau 400G QSFP-DD?

Nws tsis yog hais txog tus lej bandwidth ntawm daim ntawv spec. Daim ntawv foos uas koj xaiv hnub no kaw koj rau hauv lub hnab ntawv tshwj xeeb, lub tswv yim txias, thiab cov txheej txheem cabling rau 5-7 xyoo tom ntej. Tau txais nws tsis ncaj ncees lawm, thiab koj tab tom zaum ntawm lub peev xwm tso tseg lossis los ntshav los ntawm kev siv thev naus laus zis koj txoj kev tsheb tsis xav tau.

Cia peb rhuav qhov no raws li peb yuav tham dhau los ntawm kas fes.

 

 

Lub cev lub cev: Dab tsi tiag hloov

Nov yog qhov kev cog lus nrog QSFP-DD-"DD" sawv cev rau Ob Qhov Ceev, thiab qhov ntawd yog qhov lawv tau ua. Lawv coj tus thawj QSFP28 txuas thiab npuaj kab thib ob ntawm kev sib cuag hluav taws xob tom qab nws.

QSFP28 muab rau koj plaub txoj kab khiav ntawm 25 Gbps txhua (NRZ hloov kho), tag nrho 100G ib qhov chaw nres nkoj. Tib qhov dav nws ib txwm yog: 18.35mm. QSFP-DD muab ob npaug rau cov kab no mus rau yim, txhua qhov thawb 50G nrog PAM4 teeb liab, ntaus 400G aggregate.

Qhov ntse me ntsis? Qhov thib ob txuas kab txuas ntxiv tsuas yog kwv yees li 2.5mm rau qhov tob ntawm qhov module. Dav nyob li qub, yog li koj qhov chaw nres nkoj uas twb muaj lawm tseem ua haujlwm.

Ntawm no yog lub compatibility kicker:QSFP-DD tawb zoo siab txais tos koj cov QSFP28 qub modules-lawv tsuas yog siv cov kab sib txuas ua ntej. Tab sis tig nws ib ncig? Tsis muaj dice. QSFP-DD modules lub cev yuav tsis zaum hauv QSFP28-tsuas yog cov chaw nres nkoj vim tias qhov tob txuas ntxiv.

Spec	QSFP28	QSFP-DD
Cov kab hluav taws xob	4	8
Max Txoj kab nqes	25G NRZ / 50G PAM4	50G PAM4 / 100G PAM4
Aggregate Bandwidth	100G / 200G	400G / 800G
Module Dav	18.35mm 3	18.35mm 3
Module Qhov tob	~ 70 hli	~ 87 hli
Connector Kab	Ib leeg	Dual

Qhov kev sib raug zoo rov qab no yog qhov loj heev rau kev tsiv teb tsaws theem-ntau ntxiv tom qab thaum peb tham ROI.

 

 

Teeb meem kub tsis muaj leej twg xav tham txog

Qhov no yog qhov uas cov khoom tau txais tiag.

Ib qho QSFP28 module ntawm 100G rub ntawm 2.5W thiab 3.5W. Standard passive heatsinks nrog rau pem hauv ntej zoo - rau - rov qab airflow? Koj yog golden. Feem ntau cov hloov pauv platforms ua qhov no yam tsis muaj hws tawg.

QSFP-DD ntawm 400G? Peb tab tom tham 10W txog 15W rau ib qho module. Txuas mus txog qhov sib txawv tuaj yeem thawb 18W.

Cia qhov ntawd tso rau hauv ib pliag.Qhov ntawd yog kwv yees li 4x nce hauv thermal dissipation. Rau qhov chaw nres nkoj.

Txhawm rau muab tso rau hauv qhov tiag -lub ntiaj teb cov ntsiab lus: xav txog tej yam koj tam sim no tus neeg rau zaub mov chav AC yog qhov loj los ua kom txias lub sedan tus nqi ntawm cov cua sov ib rack. Tam sim no koj tab tom thov nws los tuav lub tsheb thauj khoom. Tib hneev taw, 4x thermal load.

Qhov no txhais li cas rau koj cov infrastructure:

Cov lej airflow hloov tag nrho. QSFP28 cov chaw nres nkoj feem ntau xav tau 20-25 CFM (cubic feet ib feeb) rau ib txoj haujlwm. QSFP-DD? Koj tab tom saib 40-60 CFM. Qhov ntawd txhais tau tias cov kiv cua nrawm dua, kiv cua ntau dua, lossis ob qho tib si.

Rau 48-chaw nres nkoj hloov, cov lej zoo li no:

Kev teeb tsa	Fais fab Draw (Transceivers nkaus xwb)
48x QSFP28 @ 3.5W	168W
48x QSFP-DD @ 15W	720W

Ntawd 552W delta rau ib qho kev hloov ntxiv nrawm nrawm hla lub pod. Yog tias koj tab tom khiav cov pa ua kom sov- hauv pem teb txias, tej zaum koj yuav tau saib tom qab- qhov rooj sib hloov cua sov los yog txhim kho qhov chaw txias txias kom ua haujlwm 400G.

 

 

PAM4: Khawv koob (thiab tsis yooj yim) Qab 400G

Okay, nrawm nrawm mus rau hauv cov teeb liab txheej -vim qhov no piav qhia ntau txog vim li cas 400G raug nqi ntau dua thiab kub dua.

QSFP28 siv NRZ signaling. Tej yam yooj yim: voltage siab=1, voltage low=0. Ib ntsis ib lub cim. Ntawm 25 Gbps ib txoj kab, nws huv si thiab tsis xav tau ntau lub teeb liab txias.

QSFP-DD siv PAM4. Hloov ntawm ob theem voltage, koj tau txais plaub. Txhua lub cim encodes ob ntsis. Koj tau ua haujlwm tau zoo dua ob npaug ntawm koj tus nqi me ntsis yam tsis tau cranking txog tus lej cim- uas tseem ceeb vim tias cov cim siab dua ntaus cov phab ntsa tsis zoo ntawm cov cim tsis zoo los ntawm kev poob thiab crosstalk.

Xav txog nws li no: NRZ yog lub teeb hloov -on lossis off. PAM4 yog dimmer hloov nrog plaub txoj haujlwm. Koj tab tom ntim cov ntaub ntawv ntau ntxiv rau hauv txhua "nias," tab sis tus txais yuav tsum yog txoj hauv kev ntau meej txog kev txheeb xyuas qhov chaw koj nyob ntawm.

Kev lag luam - tawm?Cov plaub theem voltage yog nyem rau hauv tib lub teeb liab viav vias. Txhua "kauj ruam" ntawm qib tsuas yog hais txog 1/3 qhov siab ntawm NRZ. Qhov ntawd yog kwv yees li 9.5 dB tsawg lub suab nrov- yog vim li cas FEC (Forward Error Correction) tsis xaiv tau ntawm 400G, nws yog qhov yuav tsum tau ua.

Parameter	NRZ (QSFP28)	PAM4 (QSFP-DD)
Bits per Symbol	1	2
Lub cim tus nqi rau 50G	50 GBaud	25 GBaud
Qhov muag Amplitude	puv viav vias	~ 1/3 ntawm tag nrho viav vias
SNR Requirement	qis	~ 10 dB siab dua
FEC	xaiv tau	Yuav tsum tau (KP4)

KP4 FEC (RS-544,514) ntxiv txog 2.6% bandwidth overhead thiab 50-100ns latency ib hop. Rau ntau daim ntawv thov, koj yuav tsis pom. Rau latency-rhiab trading workloads? Qhov ntawd yog kev sib tham tsim nyog muaj.

Tag nrho qhov no PAM4 teeb liab ua- sib npaug, FEC encoding / decoding, moos rov qab hla yim txoj kab -xav tau DSPs hlawv 4-6W tsuas yog ua lej. Qhov ntawd yog qhov loj ntawm yog vim li cas 400G modules khiav kub ntau dua li lawv cov 100G ua ntej.

 

 

Zaj Dab Neeg Backward Compatibility

Ntawm no yog qhov QSFP-DD khwv tau nws khaws cia rau leej twg ua ib ntus tsiv teb tsaws.

Qhov ob -kab connector tsim peb tham txog? Nws txhais tau tias koj QSFP-DD keyboards tuaj yeem khiav koj QSFP28 optics uas twb muaj lawm ntawm 100G nrawm. Tus tswv tsev kuaj xyuas hom module thaum lub sijhawm init thiab teeb tsa qhov chaw nres nkoj raws li. Tsis muaj adapter dongles, tsis muaj weird compatibility hom.

"QSFP-DD qhov rov qab ua tau zoo nrog QSFP28 tso cai rau cov tswv lag luam hauv lub network kom siv cov khoom muag 100G optics uas twb muaj lawm thaum siv 400G hloov tshiab platforms, txo cov nqi tsiv teb tsaws chaw." - Ethernet Alliance, QSFP-DD Technology Overview

Cov xwm txheej zoo li no ua rau:

Koj qhov hloov tshiab 400G txhav tuaj yeem txuas mus rau keeb kwm 100G nplooj ntawv hloov thiab 400G nplooj tshiab ib txhij. Tib chassis, sib xyaw speeds, xoom ua yeeb yam.

Lossis: koj xa QSFP-DD platforms tam sim no, sau lawv nrog koj cov khoom QSFP28 uas twb muaj lawm, thiab hloov kho ib tus neeg txuas mus rau 400G raws li cov tsheb xav tau. Tsis tas yuav hloov kho forklift.

Yog tias koj tau txais 500 QSFP28 modules zaum hauv cov khoom muag- sawv cev tej zaum $ 250K-$ 500K hauv kho vajtse- uas tsis yog kev nqis peev. Cov optics tseem ua haujlwm hauv koj qhov kev tsim kho tshiab.

Ob peb gotchas yuav tsum nco ntsoov:

QSFP28 modules max tawm ntawm 100G (los yog 200G nrog tshiab 50G PAM4 variants) tsis hais tus tswv tsev yuav ua li cas

Thermal systems optimized for 400G tej zaum yuav dhau -QSFP28 modules txias- nyob rau hauv ib puag ncig ntub, uas tuaj yeem ua rau muaj kuab paug. Qee lub platforms cia koj hu rov qab rau -chaw nres nkoj kiv cua ceev.

Fiber connector hom yuav txawv ntawm koj qhov kev siv 100G thiab 400G-xyuas cais

Rau pab pawg tswj kev sib xyaw 100G / 400G ib puag ncig,peb muabQSFP28 modulesthiabQSFP-DD transceiversnrog rau cov qauv zoo ib yam nyob rau hauv ob qho tib si cov qauv - ua kom yooj yim rau koj cov txheej txheem tsim nyog thaum hloov pauv.

 

 

Cabling: Tshiab Connectors Nkag mus rau Kev Sib Tham

Thaum koj dhia ntawm 100G mus rau 400G, koj cov kev xaiv kev sib txuas ntawm fiber ntau hloov pauv.

Yam koj tab tom khiav tam sim no (QSFP28):

LC Duplexrau ib leeg -fiber-pair daim ntawv thov (100G-LR4, 100G-CWDM4). WDM crams plaub 25G raws rau ib khub fiber ntau -txheej txheem LC thaj vaj huam sib luag kov nws zoo.

MPO-12rau cov khoom sib txuas (PSM4, SR4). Plaub fibers khub rau TX / RX, nrog plaub fibers hauv 12-ribbon zaum tsis siv. Tsis tshua muaj txiaj ntsig, tab sis nws ua haujlwm.

Dab tsi 400G coj mus rau lub rooj:

MPO-16rau parallel 400G (SR8 thiab cov phooj ywg). Yim TX, yim RX, xoom tsis siv fibers. Thaum kawg, tag nrho ribbon siv.

MPO-12 nrog breakouttseem ua haujlwm rau qee qhov 400G daim ntawv thov. Modules zoo li 400G-DR4 siv plaub 100G-ib -lambda raws, sib piv MPO-12 lub cev txheej tab sis plaub npaug sib npaug ntawm cov bandwidth.

CS (Compact Simplex) thiab SN connectorsyog qhov kub kub tshiab rau siab -qhov ceev ib leeg- fiber ntau khiav. Kwv yees li ib nrab ntawm qhov chaw vaj huam sib luag ntawm LC-Kev txhim kho fiber ntau loj ib RU.

Yog tias koj tab tom speccing tshiab cabling, xav ua ntej. Koj cov nroj tsuag fiber ntau yuav tsum ua kom haum rau ntau yam ntawm cov khoom sib txuas uas koj yuav xav tau tiag tiag hauv 5-7 xyoo tom ntej.

DAC ncav cuag qhov teeb meem ntawm 400G:

Direct Attach Cables yog qhov zoo rau luv luv -haul, tib yam - kab txuas. Tab sis lub teeb liab kev ncaj ncees teeb meem ntawm PAM4 tus nqi txiav koj mus txog qhov tseem ceeb.

Hom kab	QSFP28 100G	QSFP-DD 400G
Passive DAC	Mus txog 5 m	Txog li 2.5m
Active DAC	Mus txog 7 m	Mus txog 3 m
AOC	Mus txog 100 m	Mus txog 100 m

Qhov 2.5m passive DAC txwv ntawm 400G tuaj yeem thawb ntau ntawm koj cov kev sib txuas mus rau AOCs lossis pluggable transceivers. Ua qhov ntawd rau hauv koj li -port nqi qauv qauv.

Peb TshuagDAC cablesthiabAOC cov kev xaivthoob plaws QSFP28 thiab QSFP-DD daim ntawv yam yog tias koj ua qauv rau koj qhov kev sib txuas lus zoo.

 

 

Yog li thaum twg koj ua tiag dhia?

Tom qab tag nrho cov specs thiab thermal lej, ntawm no yog qhov peb yuav ua li cas rau kev txiav txim siab.

Lo nrog QSFP28 yog tias:

Koj qhov 100G txuas tau khiav qis dua 50% kev siv txuas ntxiv. Koj muaj lub taub hau.

Lub zog thiab cua txias txwv lub thawv rau koj, thiab 4x thermal nce yuav txhais tau tias kev hloov kho qhov chaw koj tsis tau npaj rau.

Koj cov khoom muag QSFP28 yog qhov tseem ceeb thiab tseem muaj txiaj ntsig zoo.

Koj tab tom tham txog ntug lossis ceg qhov chaw uas cov tsheb thauj mus los sib sau ua ke rau lwm qhov.

Txav mus rau QSFP-DD yog:

Qhov chaw khib yog nyob ntawm tus nqi thiab koj xav tau qhov chaw nres nkoj siab tshaj plaws (4x bandwidth, tib pem hauv ntej - vaj huam sib luag hneev taw).

Koj tus txha nraub qaum-ntxuav nplooj ntoo xav tau ntau dua qhov sib piv rau cov nplooj ntawv tuab.

Koj tab tom tsim lub chaw tshiab uas koj tuaj yeem ua tau - lub zog loj thiab cua txias txij hnub ib.

Kev sib tw lossis cov neeg muaj feem cuam tshuam yuav tsum ua kom pom cov peev txheej tom ntej -gen.

Txoj kev hybrid feem ntau orgs tau siv:

Siv QSFP-DD hloov pauv platforms nrog rov qab- cov chaw nres nkoj sib xws. Populate nrog ib qho kev sib xyaw ntawm QSFP28 thiab QSFP-DD transceivers raws li qhov xav tau txuas tiag tiag. Txhim kho kev sib txuas ntawm tus kheej raws li kev tsheb loj hlob.

Qhov no ua rau koj yooj yim rau qhov chaw optics ntawm tus nqi sib tw thaum khaws cia koj txoj kev txhim kho. Nws tsis yog ob qho tib si / lossis -nws yog "ob qho tib si, tawm tswv yim."

Hom kev xa tawm	Kev pom zoo	Vim li cas
Ntug / ceg	Nyob QSFP28	Tsawg zog, bandwidth muaj ntau
Enterprise DC	Phased migration	Tiv thaiv kev nqis peev, loj hlob maj mam
Huab/Colo	Ua kom nrawm rau QSFP-DD	Ceev ceev, sib tw positioning
Hyperscale	QSFP tag nrho-DD	Chaw nres nkoj ceev, kev ua haujlwm sib xws

 

 

 

Yuav Los: 800G ntawm Tib Lub Platform

Ib qho laj thawj ntxiv QSFP-DD ua rau kev txiav txim siab rau yav tom ntej- saib kev xa tawm: daim ntawv qhia kev nthuav dav txuas mus rau 800G.

Los ntawm kev thawb 100G-ib - txoj kab PAM4 hla yim txoj kab, thaum ntxov 800G QSFP-DD modules ntaus lub khw hauv 2024. Kev saws dav dav yuav tsum txog 2026-2027 raws li hloov ASIC kev txhawb nqa kom loj hlob.

OSFP yog qhov sib tw 800G daim ntawv foos- me ntsis loj dua nrog lub peev xwm ntau dua. Kev lag luam tseem tsis tau muaj kev pom zoo rau lub sijhawm ntev - kev taw qhia tsis tau, tab sis QSFP-DD qhov kev sib raug zoo rov qab ua rau nws muaj qhov tseeb rau kev ua lag luam.

Cov kab hauv qab: yog tias koj yuav QSFP-DD switching platforms hnub no, koj nyob nraum positioned rau 800G upgrades los ntawm transceiver swaps ib leeg. Koj qhov kev hloov kho kho vajtse peev yog hla ntau tiam neeg bandwidth.

 

 

Wrapping Up

QSFP28 vs QSFP-DD kev txiav txim siab tsis yog tiag tiag txog 100G vs 400G bandwidth. Nws yog hais txog kev sib piv koj cov peev txheej hauv vaj tse rau koj cov kev xav tau tiag tiag - tam sim no thiab qhov projected.

QSFP28 tseem ua rau kev nkag siab qhov twg 100G muaj ntau thiab koj xav tawm hws cov khoom muaj nqis uas twb muaj lawm. QSFP-DD muab qhov ceev hyperscale ib puag ncig xav tau thaum muab cov khw lag luam ib txoj hauv kev tsiv teb tsaws chaw uas tsis tso lawv cov khoom muag 100G.

Feem ntau cov kev xa tawm ua tiav peb pom muab cov kev xaiv zoo tshaj plaws rau kev xaiv platform nrog tactical yooj yooj yim hauv kev yuav khoom optics. Nkag siab txog qhov cuam tshuam ntawm thermal, npaj koj cov kab ke txuas rau kev hloov pauv ntawm cov khoom sib txuas, thiab koj yuav raug teeb tsa rau txhua yam kev loj hlob ntawm koj.

 

 

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Technical specifications txawv los ntawm cov chaw tsim tshuaj paus thiab module configuration. Nco ntsoov xyuas nrog tus neeg muag khoom cov ntaub ntawv ua ntej kev yuav khoom. Kev kwv yees kev lag luam sawv cev rau cov kws tshuaj ntsuam xyuas kev lag luam thiab yuav tsis cuam tshuam cov xwm txheej tiag tiag.

Cov ntaub ntawv:

1. IDC, "Worldwide Enterprise Network Infrastructure Forecast, 2023-2027"(Tshawb xyuas cov ntawv tshaj tawm tam sim no rau cov phiaj xwm tshiab)
2. QSFP-DD MSA Group, "QSFP-DD Hardware Specification Rev 6.0"
3. Ethernet Alliance, "QSFP-DD Technology Overview," 2023
4. Lub koom haum Uptime, "Data Center Capacity Planning Best Practices"