Heatsink and Thermal Management Guidelines for the Orca M.2 Accelerator Module

Documentation User Guides
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Overview

The DeGirum Orca M.2 2280 AI accelerator module is designed for high-performance AI inference at the edge. To maintain optimal performance and prevent thermal throttling during intensive workloads, effective thermal management is crucial. This topic provides guidelines for heatsink and airflow solutions to ensure the Orca M.2 module operates within safe thermal limits.

Thermal Management Overview

The Orca M.2 module includes internal temperature monitoring and a frequency throttling mechanism to prevent overheating. If the module exceeds a preset high-temperature threshold, the firmware automatically reduces the operating frequency until the temperature returns to safe levels. This helps avoid damage due to insufficient heat dissipation.

For environments with high ambient temperatures or extended workloads, additional cooling solutions—such as heatsink and airflow—may be required to maintain optimal operating temperatures.

Heatsink & Airflow Requirements

Thermal dissipation can be approximated by the following the formula:

\text{Ambient Temperature} + W \times R_{\text{TJA}} < \text{Maximum Operating Temperature}

Where:

W: Power dissipated by the Orca module (Watts)
R_{\text{TJA}}: Thermal resistance from junction to ambient (°C/W)
\text{Maximum Operating Temperature}: Junction temperature limit

The total thermal resistance of R_{\text{TJA}} consists of:

R_{\text{JC}}: Junction-to-case thermal resistance (0.3 °C/W)
R_{\text{CHS}}: Case-to-heatsink thermal resistance (0.12 °C/W with thermal paste or pad)
R_{\text{HSA}}: Heatsink-to-ambient thermal resistance

Example Calculation

Consider a scenario where the Orca module dissipates 3 W, the ambient temperature is 70 °C, and the recommended maximum operating temperature is 95 °C.

70\,^\circ \text{C} + 3\, \text{W} \times (0.3\,^\circ \text{C}/\text{W} + 0.12\,^\circ \text{C}/\text{W} + R_{\text{HSA}}) < 95\,^\circ \text{C}

Solving for R_{\text{HSA}}:

R_{\text{HSA}} < 5.4\,^\circ \text{C}/\text{W}

A heatsink with thermal resistance lower than 5.4 °C/W is required to maintain safe operating temperatures. The user should select an appropriate combination of heatsink type, size, and airflow to ensure a thermal resistance of less than 5.4 °C/W for this example.

Heatsink & Airflow Design Guidelines

  • Material: Use aluminum or copper for optimal thermal conductivity.
  • Dimensions: Ensure the heatsink is appropriately sized for the M.2 2280 form factor (22 mm x 80 mm).
  • Attachment: Use thermal pads or thermal paste to enhance heat transfer between the module and heatsink.
    • Airflow:
      • In environments with limited airflow, a passive heatsink may be sufficient.
      • For more demanding applications, active cooling solutions (e.g., small fans or improved ventilation) are recommended. Optimize airflow direction and placement for maximum cooling efficiency.

Example Heatsinks

Rectangular aluminum heatsink with parallel ridges and an integrated small cooling fan on the right side, featuring red and black wires connected to a white plastic connector.
Rectangular aluminum heatsink with parallel ridges and an integrated small cooling fan on the right side, featuring red and black wires connected to a white plastic connector.2375×925 291 KB
Silver aluminum heatsink with angled grooves and the logo ‘TEKQ’ on the right side, designed for effective heat dissipation.
Silver aluminum heatsink with angled grooves and the logo ‘TEKQ’ on the right side, designed for effective heat dissipation.2231×758 485 KB
Silver aluminum heatsink with vertical fins and exposed copper heat pipes running through the center, featuring the brand name ‘Acidalie’ on the front.
Silver aluminum heatsink with vertical fins and exposed copper heat pipes running through the center, featuring the brand name ‘Acidalie’ on the front.2194×713 455 KB

Example Heatsink Installations

Testing & Validation

  • Thermal Testing: Monitor the module’s temperature under typical workloads to validate the cooling solution.
  • Frequency Throttling: Observe any signs of frequency throttling, which may indicate inadequate cooling.
  • Long-Term Reliability: Keep the module within recommended temperature limits to prevent degradation and ensure stable, high-performance AI inference during extended or heavy workloads.

Conclusion

Proper thermal management is essential to the performance and longevity of the DeGirum Orca M.2 2280 accelerator module. Following these guidelines will help ensure efficient operation, even under demanding conditions. The need for a heatsink depends heavily on workload, ambient temperature, and airflow conditions. Maximum heatsink thermal resistance requirement can be approximated using the example above and can be used as a guideline for acquiring a heatsink suitable for the intended operating conditions. For further assistance, please create a topic in Product Support.