Zalman Quiet Trio

Written by Fred Hunt

April 27, 2006 | 13:41

Tags: #cnps #cnps9500 #cnps9500-at #heatpipe #quiet #review #silence #silent #vf900 #zm460-aps

Companies: #zalman


The CNPS9500-AT is the LGA775-only version of the CNPS9500-LED that Zalman have had in their line-up for some time now. There are a few differences and we consider these to be an evolutionary improvement to a product that was in itself reasonably good.

It is compatible with all LGA775 processors and supports all speeds currently available. A list of motherboards known to be compatible is viewable on the Zalman website, so we suggest you take a quick look before purchasing the CNPS9500-AT.

Zalman CNPS9500-AT CNPS9500-AT (left) versus CNPS9500-LED (right)
Opening the box you are greeted with a heatsink that weighs in at 530gm and sits tall at a whopping 125mm. You would be right in thinking that a heatsink with these extreme dimensions would have a high centre of gravity, but due to the thin composition of the fins attached to the heatpipes the weight is centrally distributed.

Compared to the CNPS9500-LED (above right) the dimensions are identical, but the fan on the LED variant is translucent and is fitted with bright Blue LEDs (as suggested by the name). They are quite a garish addition to an otherwise classy looking product, so thankfully the 775-only AT variant was not graced with illumination.

Zalman Quiet Trio CPU: CNPS9500-AT Zalman Quiet Trio CPU: CNPS9500-AT
Another non-visible difference is the inclusion of a 92mm PWM fan for the CNPS9500-AT, allowing the motherboard to control the speed of the fan according to the temperature of the CPU, which is essential to keep noise at a minimum during low processor usage. This replaces and removes the need for the Fanmate 2 controller supplied with the CNPS9500-LED (above right), therefore eliminating both the required manual adjustment and the trailing wires across the motherboard.

Zalman Quiet Trio CPU: CNPS9500-AT Zalman Quiet Trio CPU: CNPS9500-AT
Included in the packaging you will find the LGA 775 mounting kit and some heat transfer compound. Fitting of the mounting kit requires removal of the motherboard to secure the underside support plate, so upgrading of an existing computer could be a pain if it is all in situ. As you can see, it is designed to use the clearances within the LGA 775 specifications, and has a little notch, visible on the lower left hand side in the second picture, to allow for the CPU to be removed. Perfect if you wish to upgrade the processor at a later date as there is no need to remove the whole heatsink mount.

Zalman Quiet Trio CPU: CNPS9500-AT Zalman Quiet Trio CPU: CNPS9500-AT
We did encounter a small problem whilst installing the underside mounting plate. As you can see, a couple of the component legs from solder joints on the back of the board fouled the plastic of the bottom half of the mount. The second picture demonstrates what a few minutes with a sharp knife can do to solve this problem. We can't really blame Zalman for this although our test motherboard - the Gigabyte GA-81955X Royal - was listed as fully compatible.

Zalman Quiet Trio CPU: CNPS9500-AT Zalman Quiet Trio CPU: CNPS9500-AT
Once fitted, the mounting kit really does inspire confidence in its holding abilities. The four screws solidly pass through the motherboard distributing the 530gms of the CNPS9500-AT evenly through all four mounting points.

The heatsink itself is comprised of three heatpipes, which are cleverly designed in a figure eight shape to act as six heatpipes, dissipating the heat across the whole of the copper face that comes in contact with the processor.

Zalman Quiet Trio CPU: CNPS9500-AT Zalman Quiet Trio CPU: CNPS9500-AT
A simple two screw mechanism holds the CNPS9500-AT in place, fitting the front screw (by the fan) is essential as the access angle is not straight. Once it is tightened a screwdriver is used to force down the mounting clip secured by another screw. We can't stress enough that you use care and the proper size cross headed screwdriver for fitting as the tip of the screwdriver, if you were to slip, would be pointing directly as your motherboard PCB, don't say you weren't warned!

Once fitted you can see exactly how high the CNPS9500-AT sits on the motherboard, design essential for it's method of removing heat from the CPU, so please reserve your "Oh, my goodness, it's huge", comments till you read how well it does.


We ran the CNPS9500-AT on an Intel Pentium 4 3.4EE LGA775 overclocked to 3.73GHz in a Cooler Master CMStacker 830 case. We compared it against a retail Intel supplied fan, comparing for noise and heat levels.

Zalman Quiet Trio CPU: CNPS9500-AT
As you can see the CNPS9500-AT outperforms the retail fan by a considerable margin, ensuring overclocked stability with near silence. In fact, even when running at 2,650RPM (the maximum speed), I struggled to hear it over the system hard drives and the case fans. The instructions for assembly were clear and very understandable, assisted also by the build video available on the Zalman website.

Value: At £37 inc vat the CNPS9500-AT is a little expensive, but there are few others that can claim to be as silent and efficient. Nexus has the PHT-7750 Skive Tek Silent 775 CPU Cooler priced very competitively at £22.76 and the noise performance figures claimed by the manufacturer are very similar to those claimed by Zalman, but until we get one in our labs for testing we can't comment on its ability. The price difference is nearly £15 pounds, and the Nexus Heatsink is also PWM controlled. Perhaps when more products like this are released on the market the CNPS9500-AT may be forced to have its price reduced.

To summarise:

Solid Mounting
Excellent Build

Motherboard has to be removed for installation
Not 100% compatible with all motherboards

That's the CPU quietened down, now onto the GPU...
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