Quick answer
A cold plate is a metal block, usually copper, with fine internal channels, mounted on a hot chip. Coolant from the CDU flows through the channels and carries heat away. Cold plates are the heart of direct-to-chip cooling; they need a clean, specified coolant such as PG25 and fine filtration to avoid clogging.
Key takeaways
- Cold plates sit on GPUs and CPUs; other parts may still be air-cooled.
- Microchannels make filtration and fluid cleanliness critical.
- Manifolds and quick disconnects connect servers to the rack loop.
General information. Confirm the exact fluid, equipment and qualification with your hardware or CDU supplier before specifying.
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How cold plates work
Heat conducts from the chip through a thermal interface into the cold plate base. Inside, coolant flows through narrow fins or microchannels that create a large wetted area. The warmed coolant returns through the rack manifold to the CDU, which rejects the heat to facility water or air.
From chip to CDU
- Cold plate on each processor.
- Server tubing and quick disconnects.
- Rack manifold distributing flow to each server.
- CDU providing pumping, filtration and heat exchange.
Coolant requirements
- Use the fluid the server and cold-plate makers specify, commonly an inhibited propylene glycol such as PG25.
- Particles and biofilm can block microchannels: filtration and biocide control matter.
- Do not mix different coolants or top up with plain water unless the supplier allows it.
Maintenance
Track glycol concentration, pH, conductivity, inhibitor level and particulates; change filters on schedule. See the CDU coolant maintenance checklist.
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What is a cold plate in liquid cooling?
A metal block with internal channels mounted on a chip; coolant flowing through it removes heat directly from the processor.
What coolant is used in cold plates?
Usually an inhibited propylene glycol mix such as PG25 or a treated water fluid specified by the hardware maker.
How we source this page
- Facts come from manufacturer pages, datasheets, owner's manuals and standards bodies, linked under Sources.
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