液冷：Google的Brazos对CDU生态的意义

Liquid Cooling: What does Google's Brazos mean for the broaderCDU ecosystem? Googlerecentlyreleased earlyspecificationsfora liquid-to-air(L2A)CDUnamed"Brazos".LikeprojectDeschutes"thatcamebeforeitin2025,BrazossimplyannouncesaCDUreferencedesignfortheOpenComputeProject'svendorecosystem(whichcountsVertiv,nVent,andBoydasmembers)toproduce.It isnotacompetingproducttoVertiv/Boyd/nVent/Motivair's existingL2ACDU lines thatGooglewill manufacture;hyperscalersarenotinthebusinessofmakingthisequipment. VarunGovindaraj+19173448543varun.govindaraj@bemsteinsg.com ChadDillard+19173448469chad.dillard@bemsteinsg.com Primafacie,thespecificationsonBrazos-class CDUsseemrelativelylow.At6OkWofcoolingcapacity,itcannotevencooloneBlackwellrack (whichrequires-120kWofcoolingcapacity).Interestingly,Brazos-classCDUs aredesignedtodrawDCpower(vs.manyotherL2ACDUsthataredesignedforACpowerinstead) AlasdairLeslie+442077624952alasdair.leslicgbernsteinsg.com Madison Rezaei+19173448622madsonrezaci@bernsteinsg.com Webelievethese CDUs aredesignedtobe OCP compliant, andfit intolegacyhyperscalerdeployments whichtendtohaveDC power infrastructurealready.The cooling capacityof6okwdoesnotworkwellforfrontiertrainingmodels,butcansupportinferenceatthatcreatingan inferenceecosystemthatcanruninexistingfacilitieswithsimpleL2ACDUretrofitsseemslikeagoodmove(especiallywheninferencelookssettogrowfasterthantrainingthrough2030).Whilenotexplicitlystated,weinferthatthis istheprimarypurposeoftheBrazosproject. Specialist Sales SteveSong+19173448401steve.song@bernsteinsg.com Whilehardtoquantify,weseetwomid-termrisksforCDUmanufacturers.First,there isrealcommoditizationrisk ofthe inferenceCDUecosystem.BrazosspecsaremeaningfullyeasiertodeliverthanDeschutes.Whiletherewillbeaserviceattach,marginswillbelowervs.flagshiptrainingCDUs.Thedecidingfactorhereisinferencerackdensities;remainsaround60kw/rack,thenameaningfulsharecouldbecooledbyL2ABrazos-styleCDUs.Ifnot,largerDeschutes-class CDUs will beneeded instead (which wewouldexpecthavehighermarginandstickierserviceattach). Second,wemayalsoseesomehyperscalerdemandshiftfromgreenfieldtoretrofitsespecially if projectsgetdelayed.While we donot seethat in stranded capacity numbers inourdata centercapacitytracker,therehasbeen someanecdotal inputfrom companiesthattheyareseeingafewcustomers(bothhyperscalersandcolos)pushoutdeliveriesbecauseofa lack of readiness/projectdelays.We'renotsayingthisWiLLhappen,but wethinkhavingthesestandardizedL2ACDUscreatesoptionalityforhyperscalers iftheyneedtoaccelerateretrofitstomeetinferencedemandinthefuture Wedonotviewthis announcementby Googleas imminently alarmingforCDu manufacturers,especiallythosethatfocusontechnical excellenceatthetopofthestackSomelevel ofCDU commoditization was alwaysexpectedbythemarket.Whilewethinkthisannouncementacceleratesthecommoditizationtrendforlowerspec.products,westillbelieveaninnovationpremiumexistsforflagshipCDUs,andexpectittocontinueastop-tierliquid coolingtechnologyevolves. BERNSTEINTICKERTABLE INVESTMENTIMPLICATIONS WerateVertivOutperformwithatargetpriceof$416.WeratenVentOutperformwithatargetpriceof$218WerateSchneiderOutperformwithatargetpriceof310.WerateEatonOutperformwithatargetpriceof$534 DETAILS Context Hyperscalershavehistoricallypushedthe"OpenComputeProject"orOCP,anon-profitthatpublishedopen-sourcespecificationsfordatacenterhardware.FoundedbyMeta,itnowhasparticipationfromGoogle,Microsoft,andOracle(althoughAmazonisanotablemissingname)andahostofothervendors.In2025,GooglepublisheddetailsofProjectDeschutesasapartoftheOCP;thiswasa setoftechnical specifications andstandardsforcompliantLiquidto Liquid (L2L)CDUs (with2MW ofcooling capacity ata 3c approachtemperature).Vertiv,nVent,andBoydallnowhaveDeschute-compliant units available intheir productcatalogs.Yesterday,Googleannouncedthattheywouldspecifyanother CDU design-thistimeforLiquidto AirforthebroaderCDUecosystem. L2L vs. L2A: What's the difference? InourCDUprimerearlierthisweekwefocusedmostlycomparingonflagshipL2LCDUs.L2Lunitsarenamedassuchbecausetheyrejectheatbetweentwoliquidloops (thetechnologycooling systemandfacilitywatersystem).Incontrast,theL2Aconfigurationwearetalkingabouttodayonlyhas one liquid loop(thetechnologycoolingsystem)whichrejectsheatas airintothe“hotaisle"ofadatacenter.ACRAHorCRAC(ComputerRoomAirHandlerorComputerRoomAirConditioner)thenblowsthehotairoutofthehall /building.Generally,L2Lcoolingispreferredforallgreenfieldbuildsorsituationswhererackdensitiescross150kW(itismuchmoreenergyefficient).Incontrast,L2Abuildsarepreferredwhenretrofittinganexistingdatacenterbecauseitdoesnotneedthefacilitywatersystemloop(eliminatingtheneedforcomplexpipingretrofits)orwhencoolingcapacitiesrangebetween40kwto-15Okw(belowwhichplainold-butcold-aircanbeusedtoextractheatfromthechips).BothL2AandL2Larestilltypesofliquidcooling(i.e.,theyneedcoldplatesandcoolanttoextractheatfromchips),theysimplydifferintermsofhowtheyrejectheatfromtheTCStotheoutsideofthedatacenter. ThoughtsonBrazosspecifications Whenwelookatthesp