Coldplate Base Specification

Author: Brian Pilapil, Thermal Mechanical Engineer, CoolIT Systems Inc. Collection: 2026-OCP-EMEA-Summit-Cooling-Environments-And-Liquid-Cooling

Summary

This presentation introduces the initial release of the OCP Coldplate Base Specification — a vendor-neutral, de-facto industry baseline for single-phase direct-to-chip (D2C) cold plates. The specification was under community review at the time of presentation (draft available at https://www.opencompute.org/wiki/Cooling_Environments/Cold_Plate), developed and presented by CoolIT Systems. The core problem it addresses is the fragmentation across the cold plate vendor ecosystem: inconsistent definitions of what a cold plate is, incomparable performance reporting methodologies, and fragmented qualification practices that make multi-supplier procurement inefficient.

The specification deliberately avoids over-prescribing design — it does not dictate manufacturing techniques, geometries, or materials. Instead, it establishes a common vocabulary (cold plate housing/bulkhead, cold plate base, fluid connections, captive retention hardware, thermal interface material), five categories of test and validation requirements, and a compliance checklist with 16 mandatory line items. Coverage is explicitly limited to single-phase cold plates; two-phase cold plates are out of scope for this initial release. The evolving scope of "what a cold plate cools" is noted: while the primary use case is CPU/GPU direct-to-chip, the spec acknowledges that DIMMs, NVMe drives, OSFP transceivers, and any other heat-generating server components that can accept a cold plate attachment are increasingly in scope as the industry moves toward 100% liquid heat capture.

The five test categories are Leakage & Pressure, Thermal & Flow, Mechanical & Structural, Reliability & Environmental, and Cleanliness. The specification references ISO, IEC, and other industry standards for in-depth test procedures. Fluid velocity within the cold plate should be kept below 1.5 m/s to prevent erosion. Cleanliness specification requires particles above 50 microns to be absent from the fluid path after manufacturing.