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AI Infra Atlas

Compare eras

The density moved. So did the bottleneck.

Four representative facilities, drawn from the same component library. Categories overlap and are not mutually exclusive; a hyperscaler can run neocloud-style pods, and many enterprises still run pre-cloud rooms.

Pre-cloud1–5 kW/rack · PUE 1.9–2.5Open
Cloud5–15 kW/rack · PUE 1.1–1.6Open
Hyperscaler AI30–150 kW/rack · PUE 1.1–1.4Open
Neocloud40–150 kW/rack · PUE 1.1–1.35Open
Comparison of four data-center eras
AttributePre-cloudThe enterprise computer room.CloudThe warehouse-scale computer.Hyperscaler AIA power plant's worth of accelerators.NeocloudThe AI factory as a service.
Period1990s to mid-2000sMid-2000s to late 2010s2020s onwardCurrent and emerging
Rack density≈1–5 kW/rack≈5–15 kW/rack≈30–150+ kW/rack≈40–150+ kW/rack
IT load per site≈0.1–2 MW≈5–60 MW≈100–1000 MW≈20–500 MW
Typical PUE≈1.9–2.5≈1.1–1.6≈1.1–1.4≈1.1–1.35
Default coolingTraditional airChilled waterDirect-to-chip liquidDirect-to-chip liquid
Representative rackAir-cooled legacy rackEnterprise accelerator rackAdvanced liquid-cooled AI rack (NVL72-class)Advanced liquid-cooled AI rack (NVL72-class)
BuildingOffice-adjacent room or small purpose-built facilityStandardized warehouse shell, modular podsMulti-hall campus, dedicated substationModular pods, retrofit shells, rapid expansion modules
Rack density≈1–5 kW/rack≈5–15 kW/rack≈30–150+ kW/rack in AI zones≈40–150+ kW/rack
CoolingPerimeter CRAC units, underfloor plenumChilled water, containment, economizersDirect-to-chip liquid + facility water, towers or dry coolersDirect-to-chip liquid, dry coolers, immersion in some designs
PowerUtility feeder, pad-mount transformer, UPS room, dieselDedicated substation, modular UPS, busway115–230 kV interconnect, MV switchgear, 2N or distributed redundancyLeased utility capacity, on-site gas turbines or bridging power
NetworkCopper-heavy, three-tier, leased lines to carriersLeaf-spine Clos fabric, fiber-heavyScale-up interconnect + scale-out AI fabric + front-end networkHigh-bandwidth low-latency GPU fabric, dark fiber to carriers
OperationsManual, ticket-driven, physical mediaAutomated, fleet-managed, software-definedFleet-scale automation, AI-assisted operationsUtilization-driven, multi-tenant scheduling, GPU-as-a-service
NetworkingThree-tier core / aggregation / access, mostly copper to the server, carrier T1/T3 and early metro EthernetLeaf-spine Clos fabric with oversubscription tuned for mixed north-south web trafficNon-blocking or lightly oversubscribed rail-optimized fabrics (InfiniBand or Ethernet) beside a conventional front-end networkDedicated per-tenant fabrics or partitioned shared fabrics; dark fiber and carrier diversity
Software modelDedicated physical servers per application, manual provisioningVirtualization, then containers and orchestration; servers are cattle, not petsCluster schedulers, collective-communication libraries, failure-tolerant training jobsGPU cloud control plane: reservation, scheduling, health checks, tenant isolation
Business modelCost center owned by the enterprise IT departmentPublic cloud (rent virtual machines, storage and services) and wholesale colocationInternal AI products plus AI cloud services sold to customersReserved clusters and on-demand GPU-hours sold to model builders and enterprises
Primary bottleneckFloor space and cooling distribution inside an existing buildingLand, power and network reach in the right metroGrid interconnection, transformers and switchgear, and accelerator supplyGPU allocation, energized power and the speed of capital
Geographic logicNext to headquarters or the business it servesClusters near population and carrier hubs with cheap power and tax incentivesWherever large blocks of power can be energized soonestAnywhere with power available quickly: retrofits, colocation, build-to-suit and remote sites
Environmental trade-offsLow absolute energy, poor efficiency: much of the power went to cooling and conversion lossesLarge efficiency gains (PUE fell sharply) while total consumption grewHundreds of MW per campus; water use, grid impacts and embodied carbon become first-order questionsSpeed-to-power can mean on-site fossil generation; choices vary widely by operator

1990s to mid-2000s

Pre-cloud data center

An enterprise-owned room or small building on a raised floor. Individual 1U and 2U servers, SAN arrays and tape sit beside the occasional mainframe. Perimeter CRAC units blow cold air under the floor; a pad-mount transformer, a UPS room and a diesel generator keep it running. Operations are manual and physical.

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Mid-2000s to late 2010s

Cloud data center

A standardized warehouse building filled with identical racks of commodity servers, virtualized and orchestrated by software. Hot-aisle containment, chilled water, air-side economizers and modular UPS raise efficiency. A leaf-spine network replaces the three-tier tree so any server can reach any other at predictable latency.

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2020s onward

Hyperscaler AI data center

A campus-scale build with its own high-voltage substation, multiple data halls and purpose-built AI pods. Racks run tens to well above 100 kW, so direct-to-chip liquid cooling and CDUs join chillers, towers or dry coolers. A dense optical fabric links tens of thousands of accelerators that must behave like one machine during training.

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Current and emerging

Neocloud AI compute campus

A GPU-centric campus built for speed: prefabricated AI pods, leased or bridged power, liquid cooling from day one, and an orchestration layer that sells reserved clusters and on-demand GPU-hours. Utilization is the business; the control plane, tenant scheduling and job queue are as central as the substation.

DefinitionA neocloud is an AI-focused cloud infrastructure provider or GPU cloud operator designed primarily around accelerated computing rather than broad, general-purpose cloud services. It often emphasizes rapid deployment, high GPU utilization, dense clusters, flexible capacity access, specialized networking, liquid cooling, and close integration with AI developers, model-training customers, and GPU vendors.

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All values are representative ranges for the category, not audited data for any facility.