Verdict:

A perfectly good PSU, but very overpriced.

Zalman is one of the biggest advocates of the heatpipe, so it should come as no surprise that the company's latest PSU sports two heatpipes. These are used to conduct heat away from the two massive aluminium heatsinks that cool the Shottky rectifiers to a separate heatsink at the back of the PSU. This is then cooled by a very quiet, temperature-controlled 140mm fan. However, the outer casing becomes hot in the opposite corner, near the modular S-ATA sockets.

Apart from its cooling mechanism, the ZM850-HP is a traditional 850W multirail modular PSU. The presence of six 12V rails puts Zalman firmly in the 'the more 12V rails the better' camp. The rails are divided up with 12V1 being rated at 18A and responsible for powering the motherboard and half the CPU, while 12V2 is also rated at 18A and powers the second half of the CPU.

The remaining 12V3 and 12V4 rails are each rated at a hefty 28A and are responsible for powering one of the two captive 6+2-pin PCI-E cables. Meanwhile, 12V5 is rated at 18A and powers all the Molex and FDD cables (captive and modular), as well as one of the two modular 6-pin PCI-E sockets. The 12V6 rail rounds off the spec with an 18A rating and is responsible for all the S-ATA cables (captive and modular), plus the final modular 6-pin PCI-E socket.

The ZM850-HP proved to be completely stable at all load levels and was also pretty efficient, averaging 83 per cent at full load. These are commendable figures, but the high asking price of the ZM850-HP is the only feature that makes it stand out from the crowd.

• Gaming Headsets - 26th September 2008
• Dream PCs - 24th September 2008
• Headphones - 12th September 2008
• Media PC components - 22nd August 2008
• PSUs - 14th July 2008
• Multi-GPU graphics - 20th June 2008
• CPU water cooling - 17th June 2008

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