Japanese users won't have to worry about a noisy cooling fan disturbing them while they watch high-definition movies on NEC's newest computer, equipped with a Blu-ray drive, uses water-cooling instead. A prototype of the PC, called the Valuestar X VX780/GD, was on display this week at the Ceatec exhibition in Chiba, Japan.

As most Japanese live in small apartments, PCs often do double-duty as both a computer and an entertainment system. But the use of cooling fans means that PCs are not as quiet as standalone DVD players, often interrupting the movie-watching experience. The use of water-cooling means NEC's Valuestar X runs quietly, making just 31 decibels of noise, or slightly more than a whisper.

Priced at ?543,000 (US$4,612), the PC is clearly not intended for people on a budget. But for those willing to pay more for a high-end system, the Valuestar X, which is due to go on sale in December and runs Microsoft's Windows XP Home Edition operating system, offers some impressive features.

In addition to the Blu-ray drive and water-cooling system, the PC offers a digital television tuner, a 3.4GHz Intel Corp. Pentium D 945 processor, 1GB of RAM, and dual 250GB hard drives. It also includes a remote control and a 20-inch widescreen LCD (liquid crystal display) with internal flat-panel NXT speakers that provide surround sound.