Active Cool Expects to Chill CPUs

An Israeli start-up company says it has found a way to address cooling issues in advanced processors through the use of a thermoelectric heat pump controlled by its own microprocessor. Active Cool is this week launching its AC4G cooling system, which will allow processors to operate at clock speeds of up to 4 GHz without overheating, the company said.

Almost all PCs compensate for the heat caused by the electrical currents running through processors with heat sinks, which absorb and dissipate heat, and cooling fans. However, current processors are reaching the limits of what can be controlled by conventional cooling techniques, said Ronen Meir, founder and president of Active Cool.

The AC4G will cost $120 per unit, and is expected to become available through retail outlets and directly to manufacturers by January 2003, Meir said. This is much cheaper than some of the other advanced cooling techniques on the market, such as liquid cooling or vapor-phase cooling, which "have no place in the home, and even most corporate environments," said Jerry Worchel, senior analyst for Instat/MDR.

Cool Challenge

Processor heat is a large issue for PC makers, as companies like Intel and Advanced Micro Devices continue to push the boundaries of processor speed and performance. "Heat is one of the biggest problems in technology today, not just [with] PC processors," but also with integrated circuits, Worchel said.

Advances in process technologies, the techniques used to make chips, help reduce the voltage and heat characteristics of leading-edge processors. But the cooling from a process technology improvement only reduces voltage consumption by a certain level, and as more processor-intensive software programs are developed, end users will demand more and more production from their processors, resulting in more and more heat, Worchel said.

For example, current processors from Intel contain thermal control circuits that throttle back processor speed when the chip reaches its maximum heat under demanding operating conditions. This was an issue for owners of certain Toshiba laptops, who found their machines running extremely slowly or shutting down under graphics-intensive applications due to inadequate cooling systems within the notebook.

Vendors are exploring new alternatives to cooling systems. For example, Hewlett-Packard is testing a chip-cooling method based on its ink-jet technology. Also, Hitachi is developing a water-cooled system.

Selective Sensors

The AC4G system uses several different sensors on its device, which is similar in size to conventional heat sink/fan configurations but adds the thermoelectric pump to one component and a separate controller that plugs into a computer's PCI slot. The sensors detect the heat of the processor and the ambient temperature of the environment and relay that information to the microprocessor. The controller then applies power to the device, which activates a cooling plate that is placed near the processor.

The fan in the AC4G normally operates at a very low speed, which reduces the sound produced by the device. When more demanding applications such as video-editing software or 3D games are run continuously for more than four minutes, the microprocessor in the controller recognizes the increased heat radiating from the processor and speeds up the fan to a second or third level, depending on the demands of the software, Meir said.

"Active Cool has developed an interesting and innovative process. It's not going to be needed in every desktop in the world right away, but people who need that kind of performance will be interested," Worchel said.

While current PC owners might not need this level of advanced cooling, future machines with advanced processors will require this type of system, Meir said. "This will become necessary to provide a growth engine for high-tech companies like Intel," he said--adding, however, that this could take some time.