Internal Loop Liquid Cooling™
High Efficiency Liquid Cooling for CPUs & GPUs.
Internal loop liquid coolers enable server manufacturers to utilize the highest performing CPUs and GPUs in high density server and blade designs where air coolers cannot support these processors. The highest performance processors are typically the processors that draw the highest wattage (have the highest TDP—thermal design power) and require the most cooling. The superior cooling characteristics of liquid enable Asetek internal loop liquid coolers to capture more heat and transfer it into a given air stream. For example, servers that are limited to 95W TDP CPUs today can often support 130W TDP CPUs with Asetek internal loop liquid cooling.
- More efficient removal of processor heat to data center air.
- Enables maximum performance processors and GPUS (max TDP) in dense chassis.
- Lowers fan speeds, saving power and reducing noise.
- No changes required to data center infrastructure.
How Internal Loop Liquid Cooling Works
Internal Loop Liquid Cooling uses Asetek’s patented, high efficiency, sealed loop liquid cooling technology to effectively cool the highest wattage, high heat flux CPUs and GPUs. The same technology is already in service and cooling more than a million CPUs and GPUs in PCs, workstations and servers.
The illustration to the right shows a block diagram of a typical Internal Loop Liquid Cooler. Two CPUs are liquid cooled in this illustration; however any combination of CPUs and GPUs can be cooled. The cold plates remove heat from the processors and into the flowing liquid. Low power, low pressure pumps are integrated with each CPU cold plate and provide the liquid flow. Asetek Internal Loop Liquid Coolers operate at such low pressures that a pressure spike leading to a failure within a server simply cannot occur. These pumps draw cool liquid from the liquid-to-air heat exchanger, move the liquid through the cold plates and circulate it back to the liquid-to-air heat exchanger. Each pump is capable of providing sufficient flow for the cooling loop to operate effectively with the second pump stopped, providing N-1 redundancy. In addition, the pump motors are hot swappable. Regular chassis fans move air through the heat exchanger and the heat exchanger removes heat from the flowing liquid and into the air flowing through the server chassis.
The higher efficiency gained with liquid cooling delivers higher cooling performance per Watt of fan power. This enables significant power savings on the internal server fans. A liquid cooled server will typically consume 5-8% less power compared to an air cooled server. Higher performance liquid cooling makes it possible to use higher wattage processors in any given server design.
Internal Loop Liquid coolers are compatible with 1U and above form factor servers and blades. The low profile Asetek integrated pump / cold plate units have interchangeable mounting mechanisms compatible with Intel and AMD server sockets including Intel 2011 standard / narrow ILM sockets and AMD G34 sockets. Liquid-to-air heat exchangers are available in multiple form factors for operation with 40mm, 80mm, 92mm and 120mm fans and scalable to almost any performance or density requirement.
Internal Loop Liquid Coolers are 100% helium integrity tested by Asetek then filled with cooling liquid and factory sealed. Data center operators (and server OEMs) never need to touch the liquid in or refill Internal Loop Liquid Coolers.
Calculating the Benefits
Data Center Power Savings Example:
- If a 1U server draws 500W and its CPU cooling fans typically uses up to 20% of the wattage under load.
- A fully populated rack draws 21kW.
- CRAC power draw to support 21kW is 7kW per rack. (Cooling PUE = 1.34).
With Asetek Internal Loop LC:
- 8% power is saved from reduced fan speed, meaning each server is now 460W under load. A fully populated rack is 19.3kW.
- CRAC power draw to support 19.3kW is now 6.5kW.
- Total saving is 2.2kW per rack or $1,927 in net power savings per rack per year (@10 Cents/kWh).
Extreme Performance Example:
- Intel Xeon X5687 CPUs run at a stock speed of 3.6GHz.
Liquid Cooling Benefit:
- Adding liquid cooling increases heat transfer efficiency.
- Added heat transfer efficiency and a special server motherboard enable CPU overclocking.
- For example: with overclocking, the Xeon X5687 runs at 4.17GHz (a 16% improvement in speed).
- CPUs and GPUs are both overclockable for extreme performance.