Computing on the Edge–Other Design Considerations for the Edge: Part 2

Edge Server Design is a complex field that requires a delicate balance between performance, thermal dissipation, component selection, and effective airflow simulations. One of the greatest challenges in Edge Server Design is architecture and layout, as designers are dealing with 30 percent less real estate to work with when compared to traditional data center servers. This results in components being placed much closer together on the motherboard and a concentration of heat creation in a smaller area.

To overcome these challenges, designers use Computational Fluid Dynamics (CFD) applications to simulate and optimize the server design. Hot spots are identified and mitigated until a design is created that maintains all active components within their specified operating temperatures, over the entire operational range of the overall server. This is a delicate process that requires significant engineering and applied science expertise.

Another important aspect of Edge Server Design is power efficiency. Having high-efficiency Power Supply Units (PSUs) options, that support multiple voltages (both AC and DC) and multiple PSU capacities, is crucial for optimal conversion of input power to server consumable voltages. PSUs are generally rated with a voluntary certification, called 80PLUS, which is a rating of power conversion efficiency. The minimum efficiency is 80 percent for power conversion rating, with maximum efficiency currently around 96 percent. However, the higher the efficiency, the higher the price of the PSU.

Contaminant protection and Smart Bezel design is another critical aspect of Edge Server Design. GR-63-Core specifies three types of airborne contaminants that need to be addressed: particulate, organic vapors, and reactive gases. Organic vapors and reactive gases can lead to rapid corrosion, especially where copper or silver components are exposed in the server. Particulate contaminants can cause leakage, eventual electrical arcing, and sudden failures.

One method of protection employed is a Conformal Covering, which is a thin layer of a non-conductive material that is applied to the electronics in a server and acts as a barrier to corrosive elements. This layer and the material used (typically some acrylic) is thin enough that its application does not impede heat conduction. Conformal Coverings can also assist against dust build-up. However, this is not a common practice in servers due to the complexity of applying the coating to the multiple modules (motherboard, DIMMs, PCIe Cards, and more) that compose a modern server and is not without cost.

Using a filtered bezel is a common option for dust. These filters block dust from entering the server but not keep dust out of the filter. Eventually, the dust accumulated in the filter reduces airflow through the server which can cause components to run hotter or cause the fans to spin at a higher rate consuming more electricity. Periodically replacing filters is critical, but how often and when? The use of Smart Filter Bezels can be an effective solution to this question. These bezels notify operations when the filter needs to be replaced, reducing downtime and maintenance costs.

In conclusion, Edge Server Design is a complex field that requires a delicate balance between performance, thermal dissipation, component selection, and effective airflow simulations. Designers must also consider power efficiency, contaminant protection, and Smart Bezel design to create efficient and reliable servers. With the increasing costs of electricity globally and the need for energy-efficient solutions, the importance of Edge Server Design will only continue to grow in the future. Read more now.