PCIe retimers are quietly eating the motherboard heat budget
Signal integrity is solved. The thermal problem it creates is not.
PCIe retimers solve a signal-integrity problem and create a thermal one. On a dense board, each retimer is another few watts in a package that was already close to its limit.
Two board vendors have moved the retimers under a heatsink shared with the VRM. That works until a customer asks for a taller cooler or a different connector layout.
The fix is boring: more copper, shorter traces, and accepting fewer lanes per board. The alternative is a fan curve that sounds like a server.
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🔒Thermal paste myths, tested with actual instrumentation
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