NEC and Hitachi have jointly developed a new liquid cooling system for desktop PCs, which reduces PC operating noise to approximately 1/3 that of current models in Japan. The new system has been realized by adopting Hitachi's advanced CPU liquid cooling cold plate -- a part that cools a heat source by circulating antifreeze liquid within that part -- and the first hard disk drive (HDD) liquid cooling cold plate, jointly developed by NEC and Hitachi. The companies claim that the system succeeds in reducing noise level of liquid cooled PCs from approximately 30 decibels (db,) to 25db at maximum operation, a noise level quieter than that of the average home DVD recorder. The system will be employed in NEC brand consumer desktop PCs for the Japanese market in the near future.

Features of the new silent liquid cooling system



1. CPU liquid cooling cold plate with liquid cooling capability

An increase in the heat conduction of the liquid cooling cold plate by more than double that of conventional cold plates was realized by creating multiple extremely fine grooves of approximately 0.09mm in width in the heat exchanger fin inside the liquid cooling cold plate and by optimizing the liquid coolant flow channel design by adopting a newly developed "down-flow method" and considering the size of the die for pin-point channeling.

2. Less noise generation by adoption of world's first HDD liquid cooling cold plate

NEC and Hitachi were able to wrap the entire HDD in a noise absorbing material and vibration insulation as the HDD liquid cooling cold plate enables effective reduction of the rise in temperature of the HDD, achieving a reduction in noise of the HDD by more than 10db. In addition, use of a low speed radiator fan (less than 1000rpm), a low operating noise micro-pump, and high performance noise absorbing material made it possible to lower the noise of the whole system.