High end CPUs can often dissipate 130W when stressed under normal operation – and considerably more when over-clocked. While the magnitude of the power is not dramatically high, the relatively small area of the silicon die (the part of the processor containing the millions of transistors) makes the heat concentration (aka, heat flux) extremely high -- approximately 1 Megawatt per square meter.  This high concentration of heat is on par with a space shuttle re-entering earth’s atmosphere at 20,000 miles per hour, or the same intensity we’d feel from the sun if earth orbited 97% closer to it.  The maximum CPU die temperature varies but must always be maintained somewhat below the boiling temperature of water, ~100°C, so as not to damage the CPU.

Liquid is more efficient and better suited for absorbing and transferring heat than air. The fluid used in Asetek's liquid cooling solutions is roughly 780 times denser than air, and this increased density enables liquid cooling to conduct heat about 24 times greater than air alone. Everyone who has felt the difference between cooling off by jumping into a pool versus stepping into an air conditioned room has experienced the superior cooling capability of liquid. In addition to proving superior heat conductivity, the liquid cooling solution is designed to move the heat from the processor to a large radiator surface area where a quiet low speed fan exhausts the heat outside the chassis. This results in superior CPU cooling performance, better acoustics, and extra protection for the components in your computer.

Cooling fans are the principle source of noise in workstations. The noise created by fans increases as fan speed increases. The liquid cooling solution replaces the fast spinning fan generally used by CPU air cooled designs with a very quiet liquid pump. Then liquid cooling takes advantage of spreading the heat over a large radiator surface cooled by the existing low noise chassis exhaust fan to push CPU heat out of the chassis.

The heat created by the CPU increases as the work being done by the CPU increases. With air cooling, spikes in CPU work load can cause sudden increases in fan speed frequently described as fan surge. Liquid cooling systems have much greater thermal transport capability allowing fan speeds to gradually ramp eliminating fan surging.

The benefits of liquid cooling are well known to computer enthusiasts. Computer enthusiasts have endured custom installation and maintenance required by traditional liquid cooling in order to benefit from the superior performance and acoustic characteristics provided by liquid cooling. Asetek has eased the difficulty for a manufacturer to deploy liquid cooling. Specifically,

• Easy to install; four traditionally separate components are integrated into a single pump assembly. This eliminates separate reservoirs and specialized pump mounting hardware. The integrated pump is actually smaller than Intel’s reference thermal solution and mounts to the same Intel proven socket.

• Robust, highly reliable; integration enables fewer connections with fewer potential points of failure. Asetek’s proprietary low pressure design further improves reliability. The result is 50,000 hours of operating life expectancy. That is over 12 years of 12 hour per day operation.

• No end user maintenance required; the factory filled and sealed system eliminates field maintenance. Users get the benefits of liquid cooling without disruption or the extra work of routine maintenance.

• Attractive cost; the specialized design is optimized for computer thermal cooling allowing it to cost less than solutions adapted from automotive or others industries.

Asetek’s field proven, factory sealed liquid cooling technology has fundamentally changed liquid cooling by eliminating installation and maintenance issues, making it practical for widespread use in workstation for the first time.

Increasing the processor frequency is accomplished by increasing the CPU’s thermal design power (TDP), which in turn increases the heat concentration on the silicon die. As long as the CPU cooler can dissipate enough heat to maintain the critical CPU junction and case temperatures, a CPU can be safely over-clocked. The problem is, today’s CPU air coolers do not have a lot of headroom to cool a CPU beyond the rated TDP. This is especially true in harsh computing environments. Asetek's liquid cooling solutions provide superior CPU cooling – providing a safe margin for over-clocking.

The efficient integrated pump and cold plate assembly only requires about 2.5W which is frequently less power than the CPU cooling fan --Improving cooling while consuming less power.

Computer Enthusiasts have long relied on liquid cooling systems to enhance CPU performance, reduce noise and lower internal chassis temperatures. However, achieving these benefits is often painful with uncertain results. Asetek designed a solution from a clean sheet of paper solely for the computer industry as opposed to adapting automotive or other industry technology.

• Design: Integration of four separate components into a single compact reliable assembly. The pump, reservoir, electronic controller and cold plate reside in a single unit that is smaller than many traditional air cooled solutions. Thousands of engineering hours and millions of dollars have been targeted to achieve a single goal – a reliable, high performance thermal solution that is cost effective.

• Reliable: Integration enables fewer system connections which lowers the potential points for leakage. The unique system design operates at low pressure further improving reliability. Each unit is individually helium leak tested to assure the integrity of each unit. The result is that Asetek’s technology will operate over 50,000 hours without any maintenance.

• No maintenance: Special material properties are used in the construction of the system. This enables very low permeability, the escape of liquid molecules through the material walls. For example, more costly specialized hoses are used instead of hoses made from lower cost, more common materials. It is this careful attention to detail that enables the unit to be factory filled and sealed for life. Traditional solutions typically have a large separate reservoir that requires periodic refilling to replenish the liquid that permeates through the hoses. Since other systems are not sealed, they also sometimes suffer from clogging due to the growth of algae, mildew or other contaminant entering the cooling fluid. Asetek’s sealed system together with the use of specially formulated, non-toxic, anti-bacterial, anti-fungal and corrosion inhibiting cooling liquid together eliminates these types of concerns.

The resulting liquid cooler design is as simple to install as an ordinary heat sink and chassis fan. Best of all, Asetek technology provides lower system noise while out performing best in class air coolers.

The liquid cooling system has three basic elements: a very efficient integrated pump, reservoir and cold plate unit; a heat exchanger (radiator) and finally, connecting tubes to transport the liquid. The integrated pump and cold plate unit is a direct replacement for the standard CPU air cooled heat sink. One pump and cold plate unit is used in the Z400 (single CPU) while two are used in Z800 (dual CPUs) workstations.  The specialized heat exchanger is mounted behind the rear chassis fan(s) with the tubes connecting the pump and heat exchanger together.

The cold plate transfers heat from the CPU into the cooling liquid. The integrated pump assembly pushes warm liquid to the heat exchanger and draws cool liquid back to the cold plate. Asetek’s liquid cooling delivers what is equivalent to 3 metric tons of liquid per minute for every square meter of die area.  This flow rate in conjunction with Asetek’s enhanced heat transfer cold plate heat exchanger can remove heat from the surface of the processor very effectively.  Finally, the system fan(s) blow air across the heat exchanger exhausting CPU heat totally outside of the chassis, benefiting all of the other components on the motherboard.

Asetek liquid cooling technology has been thoroughly tested and certified by an independent outside lab to operate without maintenance for over 50,000 hours – that’s about 12 years assuming the workstation is used 12 hours per day, every day of the year! Each system is helium integrity tested to insure it will operate properly from the day it is put in service.

The liquid inside the system is safe, environmentally friendly, non-flamable and has anti-freeze, anti-corrosive and anti-bacterial properties. Eye or skin contact may cause temporary irritation-but will not result in permanent injury. Flushing with water is recommended to prevent any irritation. Recycling the liquid cooling system with your computer is recommended.

Asetek liquid cooling solutions use a special blend of dematerialized water and a special glycol based additives. This special environmentally friendly formulation is non-corrosive, anti-bacterial, anti-fungal resistant and can withstand a storage over a wide range of temperatures.

Helium molecules are much smaller than liquid or air molecules. Therefore, if helium molecules are successfully contained, then there is assurance that larger liquid and  air molecules will also be contained. Asetek tests 100% of all liquid cooling systems by filling them first with helium and then inspecting for integrity failures using helium detection equipment.