Zalman CNPS8900 Extreme CPU Cooler Review
By Rafael Coelho on April 26, 2012


The Zalman CNPS8900 Extreme is a low-profile CPU cooler. It has two heatpipes and a 110 mm fan. Let’s test it!

The beautiful box of the CNPS8900 Extreme has a big transparent window that allows you to see the entire cooler, as seen in Figure 1.

Zalman CNPS8900 Extreme
click to enlarge
Figure 1: Package

Figure 2 shows the contents of the box: the cooler itself, a small bag of thermal compound, a manual, a case sticker, and installation hardware.

Zalman CNPS8900 Extreme
click to enlarge
Figure 2: Accessories

Figure 3 displays the Zalman CNPS8900 Extreme.

Zalman CNPS8900 Extreme
click to enlarge
Figure 3: The Zalman CNPS8900 Extreme

This cooler is discussed in detail in the following pages.

The Zalman CNPS8900 Extreme

Figure 4 illustrates the side (or front, since the cooler has a radial symmetry). Here you see the cooler is not too tall (2.36 inches or 60 mm), which is expected since the CNPS8900 Extreme is sold as a slim cooler.

Zalman CNPS8900 Extreme
click to enlarge
Figure 4: Side view

Figure 5 reveals the front (or side) of the cooler, where you can see how the heatpipes come off the cooler base and turn around the heatsink. Keep in mind that the fins are made of aluminum, not copper as it seems. You can also notice that the fan connector is not the common type, but rather the type used on VGA coolers. The cooler comes with an adapter harness.

Zalman CNPS8900 Extreme
click to enlarge
Figure 5: Front view

Viewed from the top, you see the transparent 110 mm fan, which doesn’t have any LEDs.

Zalman CNPS8900 Extreme
click to enlarge
Figure 6: Top view

The Zalman CNPS8900 Extreme (Cont’d)

In Figure 7, you can see the bottom of the cooler. The heatpipes keep direct contact with the CPU.

Zalman CNPS8900 Extreme
click to enlarge
Figure 7: Bottom view

Figure 8 reveals a closer view of the base, which doesn’t have a mirrored look.

Zalman CNPS8900 Extreme
click to enlarge
Figure 8: Base


The first step to install the CNPS8900 Extreme is to screw the clips on the base of the cooler. Figure 9 shows the clips for use with Intel CPUs installed. AMD systems use a similar pair of clips.

Zalman CNPS8900 Extreme
click to enlarge
Figure 9: Clips installed

You also need to install the nuts on the backplate in the holes according to your CPU socket, as seen in Figure 10.

Zalman CNPS8900 Extreme
click to enlarge
Figure 10: Backplate

After those two steps, put the backplate on the solder side of the motherboard, put the cooler over the CPU, and fasten four screws.

Zalman CNPS8900 Extreme
click to enlarge
Figure 11: Cooler installed

How We Tested

We tested the cooler with a Core i5-2500K CPU (quad-core, 3.3 GHz), which is a socket LGA1155 processor with a 95 W TDP (Thermal Design Power). In order to get higher thermal dissipation, we overclocked it to 4.0 GHz (100 MHz base clock and x40 multiplier), with 1.3 V core voltage (Vcore). This CPU was able to reach 4.8 GHz with its default core voltage, but at this setting, the processor enters thermal throttling when using mainstream coolers, reducing the clock and thus the thermal dissipation. This could interfere with the temperature readings, so we chose to maintain a moderate overclocking.

We measured noise and temperature with the CPU under full load. In order to get 100% CPU usage in all cores, we ran Prime 95 25.11 with the “In-place Large FFTs” option. (In this version, the software uses all available threads.)

We compared the tested cooler to other coolers we already tested. Note that the results cannot be compared to measures taken on a different hardware configuration, so we retested some “old” coolers with this new methodology. This means you can find different values in older reviews than the values you will read on the next page. Every cooler was tested with the thermal compound that comes with it.

Room temperature measurements were taken with a digital thermometer. The core temperature was read with the SpeedFan program (available from the CPU thermal sensors), using an arithmetic average of the core temperature readings.

During the tests, the panels of the computer case were closed. The front and rear case fans were spinning at minimum speed in order to simulate the “normal” cooler use on a well-ventilated case. We assume that is the common setup used by a cooling enthusiast or overclocker.

The sound pressure level (SPL) was measured with a digital noise meter, with its sensor placed near the top opening of the case. This measurement is only for comparison purposes, because a precise SPL measurement needs to be made inside an acoustically insulated room with no other noise sources, which is not the case here.

Hardware Configuration

Operating System Configuration

Software Used

Error Margin

We adopted a 2°C error margin, meaning temperature differences below 2°C are considered irrelevant.

Our Tests

The table below presents the results of our measurements. We repeated the same test on all coolers listed below. Each measurement was taken with the CPU at full load. In the models with a fan supporting PWM, the motherboard controlled the fan speed according to core load and temperature. On coolers with an integrated fan controller, the fan was set at the full speed.

Cooler Room Temp. Noise Speed Core Temp. Temp. Diff.
Cooler Master Hyper TX3 18 °C 50 dBA 2850 rpm 69 °C 51 °C
Corsair A70 23 °C 51 dBA 2000 rpm 66 °C 43 °C
Corsair H100 26 °C 62 dBA 2000 rpm 64 °C 38 °C
EVGA Superclock 26 °C 57 dBA 2550 rpm 67 °C 41 °C
NZXT HAVIK 140 20 °C 46 dBA 1250 rpm 65 °C 45 °C
Thermalright True Spirit 120 26 °C 42 dBA 1500 rpm 82 °C 56 °C
Zalman CNPS12X 26 °C 43 dBA 1200 rpm 71 °C 45 °C
Zalman CNPS9900 Max 20 °C 51 dBA 1700 rpm 62 °C 42 °C
Titan Fenrir Siberia Edition 22 °C 50 dBA 2400 rpm 65 °C 43 °C
SilenX EFZ-120HA5 18 °C 44 dBA 1500 rpm 70 °C 52 °C
Noctua NH-L12 20 °C 44 dBA 1450 rpm 70 °C 50 °C
Zalman CNPS8900 Extreme 21 °C 53 dBA 2550 rpm 71 °C 50 °C

In the graph below, you can see how many degrees Celsius hotter the CPU core is than the air outside the case. The lower this difference, the better is the performance of the cooler.

Zalman CNPS8900 Extreme

In the graph below, you can see how many decibels of noise each cooler makes.

Zalman CNPS8900 Extreme 

Main Specifications

The main specifications for the Zalman CNPS8900 Extreme CPU cooler include:

* Researched at on the day we published this review.


The Zalman CNPS8900 Extreme is a beautiful CPU cooler, with a low profile (2.36 inches or 60 mm) and good cooling performance for this category of cooler. It presented the same cooling performance as the Noctua NH-L12, which we recently tested.

The only problem is that the product website announces it as an “ultra quiet slim CPU cooler.” It is slim, but not quiet at all. Its 110 mm fan spinning at more than 2,500 rpm makes a high-pitched annoying noise, which makes it a bad choice for HTPCs or for any application where silence is desirable.

Originally at

© 2004-15 Clube do Hardware, all Rights Reserved.

Total or partial reproduction of the contents of this site, as well as that of the texts available for downloading, be this in the electronic media, in print, or any other form of distribution, is expressly forbidden. Those who do not comply with these copyright laws will be indicted and punished according to the International Copyrights Law.

We do not take responsibility for material damage of any kind caused by the use of information contained in Hardware Secrets.