IT Networks

Exploring the Various Options for Liquid Cooling Servers


As Dell Technologies keeps innovating for progress, challenges can slow down the adoption of new solutions, especially in data centers where AI workloads are crucial. These workloads demand top-notch GPUs and CPUs, leading to questions about heat and power during deployment planning. Dell’s Smart Cooling solutions, like the Triton liquid-cooled server from 2016, aim to address these issues. Fast forward to 2024, and Dell offers advanced cooling solutions such as the DLC3000 rack used by Verne Global and modular data centers delivering up to 115 kW per rack.

Regarding cooling options, there are a few common technologies:

  1. Direct liquid cooling (DLC): It cools CPUs and GPUs directly using liquid.
  2. In-row cooling: Positioned alongside racks, it distributes chilled air precisely.
  3. Rear door heat exchangers (RDHx): They capture heat from servers’ exhaust air using liquid cooling.
  4. Enclosure cooling: This method contains heated air, cools it, and circulates it separately.

Each technology has its advantages, from cooling efficiency to energy savings. For instance, in-row coolers combined with containment capture all the heat generated by IT equipment, reducing the need for air conditioning. RDHx also captures heat effectively but requires cooler water temperatures. Combining these technologies with DLC can further reduce energy consumption by cutting down on fan power needed for cooling.

Efficiency of Server Cooling:

Various cooling solutions and techniques utilize different amounts of power to provide cooling. The diagram illustrates the annual energy consumption for various cooling methods when applied to cool a standard rack of dual-CPU servers. The bars represent the energy consumed by IT equipment and the energy consumed for cooling for each cooling method. IT energy consumption encompasses all components within the server, including internal fans. Cooling energy comprises cooling components outside the server, starting from the CDUs (coolant distribution units) or CRAHs (computer room air handlers), and extending to an air-cooled chiller situated outside the data center. This model is specifically tailored for a data center situated in the Southern United States.

The initial bar represents a standard data center utilizing air handlers placed around the perimeter of the data hall to blow air towards the servers. Introducing Direct Liquid Cooling (DLC) to cool the CPUs in each server can lead to approximately 11% energy savings compared to solely relying on air-cooling with perimeter air handlers. Replacing perimeter cooling with Rear Door Heat Exchangers (RDHx) on each rack can result in a 16% annual energy saving, with an additional 2% saving achieved by adding DLC. Deploying IT in an enclosure with an in-row cooler allows for the use of warmer water, leading to a 19% energy saving over perimeter air handlers. Finally, combining this enclosure with DLC can save 23% of the energy consumed by traditionally cooled racks.

The Advantages of Dell Technologies Solutions
Various cooling methods are available in the market, including direct liquid cooling applied to additional internal server components such as memory, network interfaces, and storage. However, Dell prefers a hybrid approach that combines liquid and air cooling, offering several benefits:

  • Increased flexibility in server configurations without being tied to a specific server cold plate design.
  • Simplified designs with fewer hoses and joints, reducing the risk of leaks.
  • Easy on-site service procedures with accessible replacement of server components.
  • Access to a wide range of servers without complexity.
    Dell’s hybrid approach is less complex, providing greater agility in cooling new processors and server platforms as they emerge.

Analysis using Dell’s in-house models indicates that the hybrid air + DLC cooled deployment, when well-designed and managed with low water temperatures, may use only 3% to 4% more energy in cooling compared to approaches that “cold plate everything,” as adopted by some other vendors, while offering the aforementioned benefits.

Embrace the Next Generation of Smart Cooling
Dell remains committed to an open and flexible cooling strategy, offering customers choices rather than a one-size-fits-all solution. These advanced data center cooling methods are transitioning from high-performance compute clusters to mainstream deployments, supporting the next generation of peak-performing servers for AI and other intensive workloads. Dell’s smart cooling solutions are already assisting numerous PowerEdge customers in enhancing overall server cooling, energy efficiency, and sustainability. For further discussions on data center cooling, visit the PowerEdge Expo area at Dell Technologies World or reach out to your account team to schedule a session with a data center cooling expert.

Cart

No products in the cart.