Zalman ZM400A-APF Power Supply

Zalman ZM400A-APF Power Supply

Written by John Yan on 5/1/2003 for PC  

Making a PC quiet is not an easy task. Not with companies like nVidia stirring up the pot with their GeforceFX Ultra cooling system. In any case, Zalman’s a company that offers a variety of products to try and reduce computer noise. The first product that we’ll look at today is their ZM400A-APF power supply.

The ZM400A-APF is a noise free 400W ATX power supply that comes in a nice black color. A power supply does generate a lot of noise with its fan and Zalman has taken steps to produce a power supply that offers a significantly reduced noise generator without sacrificing power.

As you can see, in the box are the unit, a power cord, Velcro straps, and a multi-connector fan converter so you can have four fan inputs from one of the molex connectors. The Velcro straps help tidy up the power wires after installation. The four fan converter helped tidy up the various converters I had for each fan, making the space inside my case a little cleaner and improving air flow.



One thing about the power supply that it is pretty heavy, heavier than my Antec 400W power supply. It feels like the construction is pretty heavy duty. From pictures I’ve seen of the internals it has a very big heat sink to help dissipate the heat. Thus the ability to outfit the power supply with a very quiet fan. The power connectors have both the traditional ATX and the ATX12V 2x2 (4-pin) 12V power connector. There’s also an auxiliary 5-pin power connector. The ABIT NF7-S has both the traditional ATX and ATX12V 2x2 connectors so I was able to plug in both. Six molex connectors provide you with plenty of connection options.

The ZM400A-APF’s fan speed is controlled by a heat sensing unit. As you can see from the graph, the fan will run in silent mode noiseless mode until your case temperature reaches around 45C. From 45C to about 57C the fan operates in what they call silent mode where the noise level varies from 20 to 25dB. Above 57C the fan operates in normal mode where by the noise level goes to around 30dB.



After installation of the unit into my machine, I fired the puppy up. To my surprise I was able to hear the hard drive clicking whereas before I was overwhelmed by the sound of fans. Honestly, I couldn’t hear anything but fans before the power supply was installed but now that ever loving clicking of accessing hard drives could be heard. Listening to the back of the computer, I didn’t hear a peep coming out of the back of the power supply. The ZM400A-APF ran silent and since my case temperature never went above 30C.


While I still hear a lot of fan noise from my CPU cooler, I shall alleviate that problem in my next Zalman review. But the power supply noise problem is now conquered thanks to Zalman. The ZM400A-APF is pretty expensive though coming in at close to $100 in some places I searched for. If you don’t need the 400W they do offer a 300W version that’s roughly in the $70 range. But if helping quiet your computer is your forte and you need that extra juice, then the ZM400A-APF is the way to go.
It's expensive but it sure does work well. Pick it up if you're looking for a good quality power supply that's also very, very quiet.

Rating: 8.7 Very Good

* The product in this article was sent to us by the developer/company for review.


About Author

I've been reviewing products since 1997 and started out at Gaming Nexus. After writing for a few different sites that went under, it's nice to bring back a site that's not dependent on revenue and just wants to deliver news and reviews of products.

I'm  married, and enjoy first person shooters, sports games, and real time strategy games.


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