Zalman CNPS5X SZ Review

By: Kenneth Kwok
August 5, 2011

Lately at APH Networks, we have been suffering from the 'Australian effect'. By the 'Australian effect', I mean stuff always somehow turns out to be upside down. I have no idea how this has been happening in almost every review, but hopefully that bug does not hit this review as well, or else we might be in trouble. Either way, all I know is that there are some things that are better left right side up than upside down. Take your computer's CPU heatsink/fan, for example: Have you ever tried installing it the wrong way? How did that turn out... if you are not in Australia? I don't think it would be too appropriate to have the fins or the fan touching the CPU, haha. Anyways, where were we again? Oh right, it is now time to talk about today's product. By now, I'm sure most users want to know what we will be taking a look at today. The product in particular comes to us from Zalman, a renowned force in the computer cooling market with many budget to enthusiast products that may be used to suit any need -- where the CNPS5X SZ is a CPU heatsink/fan advertised to be "ultra quiet" with powerful cooling performance. Let us see how well it lives up to their claim, and how it stacks up in today's market.

Our review unit of the Zalman CNPS5X SZ was sent to our offices in Vancouver, BC using UPS Standard from Zalman's American offices in California. The brown corrugated cardboard arrived in a timely manner, and was in near mint condition, save for the minor wear and tear to the edges of the box during transportation. Inside the package was the Zalman heatsink, with lots of packing peanuts to keep it from moving around and getting damaged along the way. This was more than enough to keep the parcel safe and looking good on arrival.

In terms of aesthetics for the retail box design, it was quite clean, while still retaining some level of sophistication to it. Using the standard Zalman colors of white, blue, light blue, and black, the packaging looks pleasing to the eye, and would probably look just as good on a hook style retail display. The front of the box is focused around two pictures of the Zalman CNPS5X SZ itself; with one perspective from the front, and one from the back. The right side has the model name written sideways down the box, while the top right has a small blue and light blue banner stating its compatibility with different processors. Found at the top left is a smaller Zalman logo, and a one year warranty badge. At the rear of the box are the specifications, as well as various features and compatibility information.

Before we dig any deeper into this review, let's take a look into the specifications of the Zalman CNPS5X SZ, as obtained from the manufacturer's website:

Powerful Cooling Performance:
- Three heatpipes and aluminum fins are designed for maximum cooling while cooler setup quickly expels hot air out of the case.
Ultra Quiet 92mm Hydraulic Bearing Fan:
- An ultra quiet 92mm fan with Hydraulic bearing is incorporated for minimized noise and excellent cooling.
PWM Fan Control:
- The PWM (Pulse Width Modulation) Fan automatically adjusts fan speed (RPM) according to the CPU’s temperature.
Easy Installation:
- The cooler is designed with tool-less installation clip, making installation convenient.
High Performance Super Thermal Grease ZM-STG2:
- The included all new high performance thermal grease ZM-STG2 maximizes heat transfer from the CPU to the base of CNPS5X for intensified cooling performance.
Versatile Compatibility
- CNPS5X accommodates a broad range of sockets:
* Intel LGA 1155 / 1156 / 1366 / 775
* AMD AM3 / AM2+ / AM2

- Dimensions: 127(L) x 64(W) x 134(H)mm
- Weight: 320g
- Materials: Pure Copper, Aluminum
- Fan RPM: 1,400 ~ 2,800rpm ± 10%
- Noise: 20 ~ 32dBA ± 15%
- Fan: Hydraulic fan
- Input Voltage: 12V
- Function: PWM Control, Auto Restart

Thermal Grease
- Color: Gray
- Capacity: 1g
- Temperature Stability: -40°C ~ +150°C (-40℉ ~ +302℉)

The retail box easily opens, thanks to the good old flap design. After it is opened, the user will find two mounting brackets, one package of push pins with some Zalman ZM-STG2 thermal paste, the instruction manual, and of course, the Zalman CNPS5X SZ itself. The heatsink is protected using a two piece plastic snap open shell to protect it from damage during transportation, and to keep dust from entering the product before it enters the user's computer. The retention brackets can be used for Intel LGA 1155, 1156, 1366, and 775 installation. The packaging itself is fairly simple, and there were not too many included accessories, which should make installation easy, with less parts and less fuss to deal with. The instructions features how to install the heatsink for all the Intel and AMD sockets, which of course includes the latest Sandy Bridge line of processors for Intel users. The usage of the push pins technically makes the installation tool-free, but we will see how tool-free it really is later on in the review.

Zalman takes a one-all approach when they designed the CNPS5X SZ. Like many value oriented parts in the market today, they have decided to integrate the fan with the heatsink. This makes the fan not changeable; in other words, it cannot be swapped out for a third party model. Even with this drawback, the heatsink still looks surprisingly good, and has that unique feeling to it in my personal opinion. The fan is enclosed by fins that surround the back in a cross shape formation, while having some of the side fins extending out a little bit past the depth of the fan. Zalman decided to use a 92mm hydraulic bearing fan in the CNPS5X SZ, and advertises it as being ultra quiet. We will see how quiet this 92mm fan actually is later in our review, but usually, smaller fans running at higher RPMs are louder than bigger fans that can run at lower RPMs.

The Zalman CNPS5X SZ has a total of 55 aluminum fins that composes the array in the aforementioned cross shaped formation. With this information, we can gather that the fin density is pretty high, and with the usage of flat fins, the aerodynamic characteristics can be a bit underwhelming compared to products such as the Noctua NH-C14. With a total surface area of around 0.3 square meters to my calculations, there should be enough space for heat to move around. It weighs in at 320g, making it a very light heatsink compared to other heatsinks we have reviewed previously. Its dimensions are 127(L) x 64(W) x 134(H)mm, which corresponds accordingly with the lower weight and the surface area of the product.

As aforementioned the Zalman CNPS5X SZ runs a single 92mm fan integrated into the heatsink. This fan can run at speeds ranging from 1400 to 2800rpm, and is controlled by the motherboard with a 4-pin PWM (Pulse Width Modulation) connector. This means it can easily scale its speed to cool the CPU, depending on the current temperature.

When it comes to the heatpipes, the Zalman CNPS5X SZ implements an interesting approach in dividing them up. From the base of the heatsink to the top of the fins, there are three copper heatpipes on each side that run up to the edges in this cross shaped design. Two are found at the very back; two more are pushed further forward, and two are found near the front on the wider part of the fins. The distribution of the heatpipes to different areas should make it easier for heat to dissipate, since they are spread around instead of concentrating at one central source. However, the downside to this design is that the heatsink isn't actually that large, so the heat may still be close by, and may not project as far as it would in a bigger heatsink.

Unlike the Thermaltake Jing reviewed by my colleague Jeremy a few months ago, the Zalman CNPS5X SZ just uses a combination of copper and aluminum that is not electroplated with nickel. Usually, nickel -- despite having a relatively low thermal conductivity of 90.9 W/mK -- is used to prevent corrosion. This is something considered desirable to retain high performance in the long run. Copper has a thermal conductivity of 401 W/mK, therefore used on both the heatpipes and the base to most efficiently distribute the heat. While aluminum, with a thermal conductivity of 237 W/mK, is used for its fins due to its lightweight nature. Overall, the lack of nickel is probably going to help it deliver better performance on review websites, but it should be something that could be considered for usage in the long run as copper is vulnerable to corrosion.

Similar to most heatsinks, all the joints are all neatly tucked in under the base, with heatpipes reaching up to the top of the heatsink. A single thin plate of copper is soldered onto the base to better pull the heat from the base to the heatpipes, and should help in the long run, as they will retain good contact after many thermal expansion and contraption cycles. However, it does not appear to me that the heatpipes are soldered to the fins, and that may cause performance degradation in the future.


Overall, installation was quite straightforward with the Zalman CNPS5X SZ. For AMD users, this heatsink makes use of the stock AMD retention bracket. That means installation into an AMD build can just use the stock mounting technique. For Intel builds such as mine, there are two included retention brackets; one for LGA 775/1155/1156, and one for LGA 1366. These retention brackets fit into the standard push pin configuration for Intel processors, and are basically plastic rings that have nubs sticking out the sides to mount the heatsink onto.

To proceed, all the user needs to do is pick the correct retention bracket, and place it such that the nubs are facing the top and the bottom of the case. This is done to ensure the heatsink is mounted in such a way the exhaust heat is taken out by the rear exhaust fan found in most cases. After the retention bracket is placed on, the pushpins are then used to attach the retention bracket to the motherboard. If one is using the LGA 775/1155/1156 bracket, there are little plastic turn switches on the side of the bracket that indicates LGA 1155/1156 or 775. Just turn the plastic switches to the appropriate side, and then secure this bracket with the included pushpins. The only downside to this design is the retention brackets are quite large, and require clearance area around the CPU to properly install.

Lastly, the user just has to align the heatsink, so the fan is facing opposite of the rear exhaust fan. Most of the time, this would mean the fan is facing the front of the case. After aligning it, the screws on the two sides of the heatsink must be untightened using a screw driver. Afterwards, place the heatsink onto the bracket, push in the side screws until the metal openings align with the plastic nubs, and tighten. Installation is quite easy overall, but it was not as tool-less as asserted earlier, because a screwdriver is still needed to actually secure the heatsink properly.

The Tests

The following are the specifications of our test system, and relevant information towards our testing methods:

CPU: Intel Core 2 Quad Q9550
Motherboard: ASUS P5E3-Deluxe
Graphics: Palit Radeon HD 4850 Sonic (512MB)
Memory: OCZ Gold PC3-10600 4x1GB
Chassis: NZXT H2 (3x NZXT 120mm fans)
Power: Cooler Master Silent Pro M 1000W
Sound Integrated
Optical Drive: LG 16X DVD Burner
Hard Drive: Seagate Barracuda 7200.11 640GB
Operating System: Microsoft Windows 7 Professional

All tests were run on a custom built test platform. The computer remained in the same location in the same room throughout all tests, with a room temperature at approximately 27c. Arctic Cooling MX-2 thermal paste was used for its performance; all pastes were given a proper amount of time for them to fully settle. The fans on all heatsinks are directly connected to the motherboard's 4-pin connector, with ASUS Q-Fan "Optimal" setting enabled. Our computer was turned on for at least one hour for the idling tests. High CPU load results were obtained using Prime95 multithreaded in-place large FFTs test with four worker threads on for a minimum of 30 minutes.

As with APH Networks philosophy on heatsinks, we have decided to just test it against our previous heatsink used. We chose this method because it is hard to simulate two scenarios exactly the same way, since there are many varying factors that are very difficult to control. We try to ensure that it is as similar as possible to provide the best temperature measurements in this test.

The readings seen on our graphs above and below were the CPU temperature readings taken from Core Temp -- data provided by the processor's Digital Thermal Sensor. In the tests, the core with the highest temperature was recorded with the results being cross-checked with Real Temp to ensure the most accurate temperature readings. Also, I have made sure that the entire heatsink is heated properly beforehand to verify the idle state temperature after a full load cycle.

From the results above, we can see that the Zalman CNPS5X SZ falls a little bit behind our OCZ Vendetta, which we have used for testing against the Zalman heatsink, due to the more budget oriented market of the two. There is only a 2c difference between the two temperatures in idle. The OCZ Vendetta is also a slightly bigger heatsink with a separate mounted fan, which explains the slight difference in temperature. These results are still pretty good for a heatsink of this size and caliber.

The load results are also quite similar to the idle results in terms of the two heatsinks. The Zalman CNPS5X SZ narrowly beat out the OCZ Vendetta by 1c. Both heatsinks are not necessarily the best on the market by a long shot, but they are still quite a bit better than the stock cooler, which can easily run 10-20c higher in idle and load conditions. That is not to mention how loud the stock cooler is compared to third party solutions. Keep in mind that the room temperature was around 27c at the time of testing, so this did bump up the overall temperatures quite a bit.

Noise is a major topic for a lot of people when it comes down to picking a heatsink, from silent PC enthusiasts like our Editor-in-Chief Jonathan Kwan, to other staff members here at APH Networks, I'm sure most of us enjoy having a quiet environment to work instead of hearing our computer fans blowing louder than our music all day long. On a scale from 0 to 10, where 0 is completely silent and 10 is the loudest, I would rate the Zalman CNPS5X SZ at around a 2.5 on idle, since it is barely audible. You will need to get pretty close to even hear its buzzing noise. At full load, I would rate it at around 4.5, since it is quite audible due to the small fan size running at high speeds. Either way, it operates at a decent noise level for a heatsink in the budget oriented market, and it is definitely a much better than the Intel stock cooler.


So how well did the Zalman CNPS5X SZ stack up against the competition? Surprisingly well; especially if you want to boot your stock cooler with something that would keep your wallet happy. Retailing for around $30 at press time, there is definitely a lot to like about the Zalman CNPS5X SZ. From its relatively easy installation to a decent design, there is quite a bit packed into this $30 package. The use of AMD-style retention brackets really helps Intel users, making the installation quite painless, and it doesn't require the user to install an aftermarket backplate. An aftermarket backplate could mean removing the motherboard to properly install the heatsink. The smaller size of the heatsink in conjunction with decent performance is also a welcome addition, since quite a few budget oriented heatsinks can be both loud and ineffective. In terms of cooling performance, it does a decent job of dissipating heat, and should also do quite well in the long run, due to the welded piece of copper on the base of the heatsink. I would like to see the heatpipes soldered to the fins as well though. On the other hand, this installation system can be a bit bulky for some Intel builds, since the aftermarket retention bracket is quite large, and requires some clearance room on your motherboard. Also, the fan's noise increases noticeably at high loads, due to the 92mm fan running at a faster rate. In a sense, it is pretty close to being "ultra quiet" on idle, but it is not necessarily that when on high load. Regardless of which, for a budget oriented product, this was quite a bit more than I expected to get -- in a good way. Overall, the Zalman CNPS5X SZ does a good job, and should be considered by users who are still using the stock heatsink, and are looking for a good budget alternative.

Zalman provided this product to APH Networks for the purpose of evaluation.

APH Review Focus Summary:
7/10 means Great product with many advantages and certain insignificant drawbacks; but should be considered before purchasing.
-- Final APH Numeric Rating is 7.0/10
Please note that the APH Numeric Rating system is based off our proprietary guidelines in the Review Focus, and should not be compared to other sites.

Looking to upgrade from the Intel stock cooler with something easy on the wallet? Take a look at the Zalman CNPS5X SZ -- it performs relatively well at relatively low noise levels.

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