TL;DR: The 1.6T OSFP224 DAC is available in both Finned Top (IHS) and RHS (Riding Heat Sink) designs, with full interoperability between the two. Whether your rack uses air-cooled switches, liquid-cooled AI servers, or a mix of both, one DAC product line covers every thermal scenario—reducing SKU complexity and simplifying inventory management across heterogeneous infrastructure.
Understanding the Two Thermal Form Factors
| Feature | Finned Top (IHS) | RHS (Riding Heat Sink) |
|---|---|---|
| Cooling Fins | Integrated into module connector top | None on module; fins ride on host cage |
| Module Height | ~13 mm | ~9.5 mm |
| Thermal Responsibility | Module-level (self-contained) | Host-level (cold plate or system heatsink) |
| Cooling Method | Air-cooled | Air-cooled & liquid-cooled |
| Host Compatibility | Standard OSFP cages | Dedicated RHS cages |
| Best For | Air-cooled switches, routers | Liquid-cooled AI servers, high-density racks |
Finned Top (IHS) — Integrated Heat Sink modules feature cooling fins built directly into the OSFP connector metal top, with a total module height of approximately 13 mm. Heat is dissipated through host airflow across the integrated fins, making this design ideal for standard air-cooled Ethernet and InfiniBand switches where airflow is predictable and well characterized.
RHS (Riding Heat Sink) — Also known as “Flat Top,” RHS modules deliberately omit the integrated heat sink, presenting a flat metal surface that is only 9.5 mm high. Thermal management shifts to the host platform: a spring-loaded riding heat sink or cold plate mounted above the cage makes direct contact with the module surface when inserted. This approach is a key enabler for direct liquid cooling (cold plates) and high-density air-cooled designs where a shared heatsink serves multiple ports.
Why One Cable Family Covers Every Configuration
The real advantage of the 1.6T OSFP224 DAC portfolio is not just that both thermal designs exist—it is that they work together. The product line is available in three configurations:
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OSFP IHS Trunk — both ends Finned Top
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OSFP RHS Trunk — both ends Flat Top
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OSFP RHS ↔ IHS Hybrid — one end Finned Top, one end RHS
This hybrid capability is where deployment flexibility becomes a tangible operational benefit. Consider a typical AI cluster deployment: a 1.6T OSFP224 IHS port on an air-cooled switch needs to connect to two 800G OSFP224 RHS ports on a liquid-cooled GPU server. With a hybrid breakout cable, this is a single part number—no adapters, no extra transceivers, no additional fiber management.
For network architects, this means:
| Scenario | Without Hybrid DAC | With Hybrid DAC |
|---|---|---|
| Air-cooled switch → liquid-cooled server | Adapter + extra module + fiber | Single hybrid DAC cable |
| Mixed vendor racks (IHS and RHS cages) | Separate SKUs per rack type | One SKU covers both |
| Future migration from air to liquid cooling | Replace entire cabling infrastructure | Reuse cables, swap only host cooling |
The Real-World Impact: Fewer SKUs, Simpler Inventory
Data centers rarely deploy a single, uniform cooling architecture. A typical AI data center may house air-cooled top-of-rack switches alongside liquid-cooled GPU servers, with different vendors and generations coexisting in the same facility. Managing separate DAC inventories for IHS-only and RHS-only configurations multiplies SKU count, complicates spare-parts planning, and increases the risk of mis-insertion during maintenance.
A unified 1.6T OSFP224 DAC portfolio solves this by enabling one cable family to serve all thermal configurations. Network operators can standardize on a single product line, reduce spare inventory, and eliminate the “which cable goes where” confusion that slows down rack deployments.
Choose Your Configuration, Not Your Vendor
The 1.6T OSFP224 DAC portfolio delivers:
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Full thermal coverage — Finned Top for air-cooled switches, RHS for liquid-cooled servers
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Hybrid interoperability — IHS ↔ RHS cables for mixed environments
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Simplified inventory — One DAC family, fewer SKUs
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Future-proof migration — Reuse cables as cooling architectures evolve
Contact us to discuss which thermal configuration fits your rack design, or request samples for evaluation.
