The Open Compute Project has published the final version of the Mt. Diablo Disaggregated Power Rack Specification v1.0.0, a design for a separate "sidecar" rack that takes power conversion out of the IT rack. Microsoft, Meta and Google are listed as the authors. The document took effect Oct. 8, 2026, and its revision history labels it the "Final release." Days later, at the OCP Global Summit in San Jose, OCP leaders said single-rack power is on track to pass 1 MW, and Meta, Nvidia, Cooler Master and Flex showed hardware built around liquid cooling and 800 VDC power.

What the spec covers

The specification's scope ties the design to rising rack density: "With increased rack power (from 33kW to 100’s of kW)," it says, the disaggregated power rack, "also known as sidecar," provides "a flexible and evolving infrastructure solution." According to the document, the power rack "can be scalable and updated to meet various power requirements from 800kW to 1MW+ (with the option to parallelize power racks together) while keeping the disaggregated IT rack the same."

That last clause describes the design's basic premise. Power equipment sits in its own rack beside the compute rack, so the power side can be scaled or updated, or several power racks can be run in parallel, while the IT rack it feeds stays the same.

The v1.0.0 revision made several terminology changes. Its change log says the authors "Updated 800Vdc to “differential 800Vdc” everywhere," replaced the earlier name "Diablo 400" with "Mt. Diablo," and replaced HVDC with LVDC in the section 5 diagrams. According to the revision history, the 1.0 release followed a 0.5.x series in May 2025, version 0.7 in February 2026 and version 0.7.0 in March 2026.

OCP's case for 1 MW racks

In an Oct. 12 blog post reprinted by StorageNewsletter, three OCP executives, James Kelly (vice president for market intelligence and innovation), Cliff Grossner (chief innovation officer) and Zane Ball (chief technology officer), wrote that rack power densities are "on track to reach and then surpass 1MW in a single rack." The post said OCP had launched an Open Data Center for AI strategic initiative covering power, cooling, mechanical and management telemetry, following an open letter from Google, Meta and Microsoft.

The summit announcements listed in the post also included a white paper covering current plans for 800 VDC distribution and the evolution to 1,500 VDC, a requirements specification for solid-state transformers that convert medium voltage to 800 VDC, new Open Rack ORW/HPR designs that double the rack's width and raise its power profile, and the version 1.0 Deschutes coolant distribution unit (CDU) specification. OCP also announced alliances with EPRI and Current/OS on interaction between data centers and the power grid. The post cited an IDC projection that more than $890 billion in IT equipment based on OCP-recognized designs will change hands by 2030.

Meta's liquid-cooled network rack

In an Oct. 12 post on its engineering blog, Meta introduced IcePack, which it describes as its first-generation liquid-cooled network rack, built on the OCP ORV3-HPRv1 rack standard. The rack houses IceCube, a 102.4 Tbps fabric switch with 128 ports at 800G, offered in versions based on Broadcom Tomahawk6C and NVIDIA Spectrum-6. Meta says the new generation "represents a 2x bandwidth increase over our 51.2T platforms while achieving the thermal density required for next-generation AI data centers."

The same post covers a Flattened Planar Fabric that Meta developed in collaboration with NVIDIA, and the Open Switch Platform Architecture (OSPA), a new OCP initiative that Meta says it co-leads with Microsoft and Alibaba. Meta also gave scale figures for its own campuses: Prometheus at roughly 1 gigawatt in 2026, and Hyperion scaling toward 5 gigawatts.

Nvidia, Cooler Master and Flex

Network World reported Oct. 15 that Nvidia submitted the rack and compute tray designs for its Vera Rubin platform to OCP through its modular MGX architecture. The outlet wrote that in these designs "there are no fans or cabling because everything is liquid cooled."

Cooler Master showed a 2,500 kW liquid-to-liquid CDU. According to the company, it moves up to 990 gallons of coolant per minute and can manage up to 32 interconnected CDUs. Flex presented prefabricated AI modules that combine an 800 VDC power rack with CDUs. Flex claims the modules can speed deployment of AI infrastructure by as much as 50% compared with traditional construction methods.

Context

The same three companies named as authors of the Mt. Diablo specification, Microsoft, Meta and Google, also signed the open letter that OCP says led to its Open Data Center for AI initiative. Meta and Microsoft are also co-leading the OSPA switch-platform work with Alibaba. Meanwhile, the voltage class the final spec now calls "differential 800Vdc" is the focus of OCP's 800 VDC distribution white paper and is used in Flex's power rack.

What Happens Next

Cooler Master is targeting mass production of its 2,500 kW CDU in Q4 2026, according to Network World. Nvidia's Vera Rubin rack and compute tray designs have been submitted to OCP through MGX. The Open Data Center for AI initiative and the OSPA effort are both newly launched OCP initiatives, and their sources give no schedule for deliverables.

Sources