Zalman CNPS9900 MAX CPU Cooler Review

If it wasn't just because of the CNPS10X Extreme CPU Cooler, I'd say Zalman definitively bets to produce coolers based on their unique design. I can really argue on how full tower coolers can be better for extreme overclockers or people who just want to push their hardware to the limits in non-extreme conditions. So let me start this review going 2 weeks back in time when I received the Zalman CNPS9900 MAX. Of course I was thinking this could be a good cooler, but I really couldn't think on how it could compete in the major leagues. Some days after that, we received a "reviewer's guide", with detailed features and comparisons about this new product. I started reading it when I got surprised; there was a chart comparing the CNPS9900 MAX against the Thermalright Venomous X full-tower cooler and the CNPS10X too, and the CNPS9900 MAX was showing the best performance among the competition. Of course, being this from the manufacturer, I needed to take it with a grain of salt, but I was just ready to try and obtain similar results, or simply explain how sad reality is in this article. Additionally, the Venomous X was tested with an ADDA AD1212HF-A7BGL fan spinning at 2,200rpm and moving 85CFM.

OK, so that's how I got really interested on testing the Zalman CNPS9900 MAX, as Zalman had some very convincing features including 3 heat-pipes being equivalent to 6 (U-shaped) heat-pipes, a 135mm fan, and a very appealing black-pearl nickel plating including a mirror-finished base. Also, Zalman is launching a new heat-pipe design which is supposed to be 50% more effective in heat transfer compared to ordinary heat-pipes. Through my review, I'll test the CNPS9900 MAX against the very popular Prolimatech Megashadow, and a pair of dual-tower heatsinks: the Cogage Arrow (pretty much the same as the new TR Silver Arrow) and the Noctua NH-D14. Before starting, let me get things straight. Don't expect tons of charts with different fans as the CNPS9900 doesn't have the ability to change its fan. However, keep in mind this CPU heatsink utilizes a 135mm fan (while other normally support 120mm fans) and it's said to work at 1500 and 1700 rpm as shown in the specifications below. You can't install a second fan either, but I'll test with 2 different CFM configurations; one quiet and another one not very quiet, but enough to move similar CFM as the fan shipped with the CNPS9900 MAX. For more detailed information about our testing methodology please read the next pages.

Zalman CNPS9900 MAX Features

• Powerful Cooling Performance Qmax: 300W
• Ultra Quiet 135mm Blue/Red LED Fan
• PWM Fan Speed Control
• Black-Pearl Nickel Plating
• Super Thermal Grease ZM-STG2
• Versatile Compatibility

CNPS9900 MAX Specifications

• Dimensions: 94(L) x 131(W) x 152(H) mm
• Weight: 755g
• Material: Base & Heatsink: Pure Copper
• Dissipation Area: 5,402 cm²
• Heat-pipes: 3 Ω (Omega) Shaped Heat-pipes - Equivalent to Performance of 6 Heat-pipes
• Fan: PWM 135mm Blue/RED LED Fan
• Fan Speed Quiet Mode: 900 ~ 1,500 rpm ± 10%
• Fan Speed Normal Mode: 900 ~ 1,700 rpm ± 10%
• Fan Noise Quiet Mode: 18 ~ 27 dBA ± 10%
• Fan Noise Normal Mode: 18 ~ 30 dBA ± 10%
• Input Voltage: 5V (Quiet Mode), 12V (Normal Mode)
• Bearing Type: Long Life Bearing 50,000hrs or greater
• Supported Sockets: Intel Socket LGA1366/1156/775 & AMD Socket AMD/AM2/AM2+
• Thermal Grease: ZM-STG2
• Thermal Grease Color: Gray
• Thermal Grease Capacity: 3.5g
• Thermal Grease Temperature Stability: -40°C ~ +150°C (-40? ~ +302?)

Full Disclosure: The product sample used in this article has been provided by Zalman.

Closer Look: Zalman CNPS9900 MAX

Aside from a pretty looking box, with all the features I'll talk about printed on it; let's get straight to the product. As you can see, the Zalman CNPS9900 MAX looks pretty awesome. The black-pearl nickel plating is good enough to make it look like a black-edition cooler, and definitively looks better than the normal cooper-colored products. Everything including the base, the heat-pipes and the fins is painted in black, except for the 135mm fan.

If you didn't notice, there are 3 omega shaped heat-pipes going from the base through the fins. Two of them go directly to one heatsink, while the third one goes to the rest. This is done to improve performance. In the next picture, the air¡-flow would go from left to right. This means it enters from the left side (single heat-pipe), which is thinner than the right side of the heatsink (dual heat-pipe). Considering that the side receiving air directly from then 135mm fan is being cooled better than the rest, that's the reason they included 2 heat-pipes and thicker fins there. There's no possibility to mount a second fan to the CNPS9900, which hinders maximum performance, but in exchange, Zalman uses no frames around its 135mm fan, which should result into a quieter CPU cooler.

If we look it through a higher-angle, it's easier to notice how 2 heat-pipes are routed inside the thicker side of the heatsink, while only 1 heat-pipe passes through the frontal fins. The sticker at the front of the fan indicates the position we should use to install the heatsink in our case. The air-flow should be routed through the rear/top of the case, and not the other way to achieve maximum performance.

Here's another point of view. Whether you like it or not, the Zalman CNPS9900 MAX will easily improve your PC aesthetics and it can be easily mixed with different motherboards and cases without breaking the pattern.

Aside from that, the box includes a little syringe with Zalman's ZM-STG2 thermal grease, a wrench for installation, a cable resistor to reduce fan's voltage, the motherboard's backplate, a full user's manual and all the bolts, nuts and screws to make the installation. I'm happy to know they didn't include generic thermal grease, but instead, a syringe which will last for 3-5 installations at least.

Join me in the next section as I continue examining this CPU cooler.

Zalman CNPS9900 MAX Heatsink Details

A closer look to the fan just reveals its transparent color which is very common nowadays for LED fans. The fan sits in the middle of the heatsink, thus forcing fresh air to enter from one side, and pushing air through the back. One thing I'd change here would be the non-included black cable-sleeving, as it would look better than without it, especially because the cable comes with the standard yellow/green/black colors breaking the whole scheme if you have a completely sleeved PSU.

Here's a closer look at the Thermal Grease and the RC7P cable resistor. Without this resistor, the fan works at normal mode, going from 900 to 1700rpm. Adding it would change the profile to silent mode, running from 900 to 1500rpm only. For lowering fan speed to 900rpm, you'll need a PWM-capable motherboard with a 4-pin header. Otherwise, it will always run at 1500 or 1700rpm.

Zalman has not opted for HDT technology, so we still have a flat, mirror-finish base. Instead, Zalman opted for Composite heat-pipes as explained below.

Without digging a lot into details, composite heat-pipes are supposed to increase heat transfer rate by 50% over conventional heat-pipes. Zalman does this by mixing "Sintered Metal" type wicks and high thermal conductive "Axial Grooves". In theory, this looks quite interesting, but we would need to test the same heatsink with these 3 types of heat-pipes in order to see if there really is a noticeable advantage. Unluckily, that's not going to happen.

You can purchase the blue LED or the red LED version, but you can't change LED color on the fly. The sample we received features a nice red LED, which goes extremely well with the ASUS Maximus III Formula motherboard and ATI Radeon cards, but some of you will prefer the blue LED edition to mix it with GIGABYTE'S motherboards or Nvidia GPUs.

Zalman opted for a new installation methodology compared to their last coolers. I strongly recommend removing the motherboard out of the case in order to get things done. I installed the CPU Cooler inside the Corsair Obsidian 700D chassis making use of the CPU back-plate's door. Even that, I struggled a lot to install the cooler on its position because the installation method isn't very well designed. The first step is to screw the CPU retention brackets into the cooler's base. That part is quite easy, but then, you need to glue (yes!) the CPU backplate with some double-sided tape. Zalman included 3 sets of double-sided tapes, so you'll need to think a lot before removing several times this cooler, as you will run out of tape. I really think this could have been avoided if Zalman included larger nuts and bolts for installation.

After that, here comes the best part; screwing the bolts with the included wrench. It was a real pain to screw the 4 frontal nuts with this oversized tool. The wrench is thin enough to become a little bit fragile and difficult to handle, but long enough to collide with everything around your CPU, including RAM slots, GPU and even the chassis. It took me about 3-5 minutes to screw every bolt into its place, which I think is a real pain considering I can screw any other thing in 10 seconds with a screw-driver. Problem is, the location of the bolts and the size of the heatsink make the use of another tool impossible, so you'll need to stick with the included wrench and have some real-bad time trying to install the heatsink unless you swap out your motherboard and take off any RAM/PCI devices connected.

Well, after all that pain, this is how the cooler looks installed in my system. In the photo above, you probably didn't notice the red LED, but I promise it's turned on. In the picture below, you'll notice the red LED barely produces a light glow. The ASUS ROG logo shines more than the included LED on the 135mm fan. I still think it looks cool and it's OK, but others might be disappointed as they expect their machine to look like a disco or a midnight club at full party (no offence).

Uninstalling the heatsink gets even worse. When I was ready to uninstall it and put another heatsink for some tests, I had to pass through the wrench pain again, and after that, you'll discover the double-sided tape glued all over the back of your CPU socket. It takes some extra time to remove it all, and the removed tape becomes un-usable, so this confirms you will be able to install it only 3 times (with the accessories included). Serious Zalman, what were you thinking? You should really improve this installation method or prepare to face some angry users. The best installation methods I've seen out there are far better than this. Normally, the best method is to install the whole CPU retention plate and bolts and nuts, and after that, leave some space to install the heatsink with some screws. Zalman opted for a bracket that cannot be installed separately, so you need to install it with the CPU heatsink at the same time, and you need to glue it on the back because other way you would need to be an octopus to have enough hands. As if that wasn't enough, installing the heatsink with a wrench instead of a screwdriver just makes things worse, and if you're installing it inside of your PC case, you'll end with a massive head-ache.

In the next section Benchmark Reviews explains our CPU cooler preparations, installation and testing methodology.

Contact Surface Preparation

Processor and CPU cooler surfaces are not perfectly smooth and flat surfaces, and although some surfaces appear polished to the naked eye, under a microscope the imperfections become clearly visible. As a result, when two objects are pressed together, contact is only made between a finite number of points separated by relatively large gaps. Since the actual contact area is reduced by these gaps, they create additional resistance for the transfer of thermal energy (heat). The gasses/fluids filling these gaps may largely influence the total heat flow across the surface, and then have an adverse affect on cooling performance as a result.

Thermal Paste Application

The entire reason for using Thermal Interface Material is to compensate for flaws in the surface and a lack of high-pressure contact between heat source and cooler, so the sections above are more critical to good performance than the application of TIM itself. This section offers a condensed version of our Best Thermal Paste Application Methods article.

After publishing our Thermal Interface Material articles, many enthusiasts argued that by spreading out the TIM with a latex glove (or finger cover) was not the best way to distribute the interface material. Most answers from both the professional reviewer industry as well as enthusiast community claim that you should use a single drop "about the size of a pea". Well, we tried that advice, and it turns out that maybe the community isn't as keen as they thought. The example image below is of a few frozen peas beside a small BB size drop of OCZ Freeze TIM. The image beside it is of the same cooler two hours later after we completed testing. If there was ever any real advice that applies to every situation, it would be that thermal paste isn't meant to separate the two surfaces but rather fill the microscopic pits where metal to metal contact isn't possible.

After discussing this topic with real industry experts who are much more informed of the process, they offered some specific advice that didn't appear to be a "one size fits all" answer:

1. CPU Cooling products which operate below the ambient room temperature (some Peltier and Thermo-electric coolers for example) should not use silicon-based materials because condensation may occur and accelerate compound separation.
2. All "white" style TIM's exhibit compound breakdown over time due to their thin viscosity and ceramic base (usually beryllium oxide, aluminum nitride and oxide, zinc oxide, and silicon dioxide). These interface materials should not be used from older "stale" stock without first mixing the material very well.
3. Thicker carbon and metal-based (usually aluminum-oxide) TIM's may benefit from several thermal cycles to establish a "cure" period which allows expanding and contracting surfaces to smooth out any inconsistencies and further level the material.

The more we researched this subject, the more we discovered that because there are so many different cooling solutions on the market it becomes impossible to give generalized advice to specific situations. Despite this, there is one single principle that holds true in every condition: Under perfect conditions the contact surfaces between the processor and cooler would be perfectly flat and not contain any microscopic pits, which would allow direct contact of metal on metal without any need for Thermal Interface Material. But since we don't have perfectly flat surfaces, Thermal Material must fill the tiny imperfections. Still, there's one rule to recognize: less is more.

Surface Finish Impact

CPU coolers primarily depend on two heat transfer methods: conduction and convection. This being the case, we'll concentrate our attention towards the topic of conduction as it relates to the mating surfaces between a heat source (the processor) and cooler. Because of their density, metals are the best conductors of thermal energy. As density decreases so does conduction, which relegates fluids to be naturally less conductive. So ideally the less fluid between metals, the better heat will transfer between them. Even less conductive than fluid is air, which then also means that you want even less of this between surfaces than fluid. Ultimately, the perfectly flat and well-polished surface is going to be preferred over the rougher and less even surface which required more TIM (fluid) to fill the gaps.

This is important to keep in mind, as the mounting surface of your average processor is relatively flat and smooth but not perfect. Even more important is the surface of your particular CPU cooler, which might range from a polished mirror finish to the absurdly rough or the more complex (such as Heat-Pipe Direct Touch). Surfaces with a mirror finish can always be shined up a little brighter, and rough surfaces can be wet-sanded (lapped) down smooth and later polished, but Heat-pipe Direct Touch coolers require some extra attention.

To sum up this topic of surface finish and its impact on cooling, science teaches us that a smooth flat mating surface is the most ideal for CPU coolers. It is critically important to remove the presence of air from between the surfaces, and that using only enough Thermal Interface Material to fill-in the rough surface pits is going to provide the best results. In a perfect environment, your processor would mate together with the cooler and compress metal on metal with no thermal paste at all; but we don't live in perfect world and current manufacturing technology cannot provide for this ideal environment.

Mounting Pressure

Probably one of the most overlooked and disregarded factors involved with properly mounting the cooler onto any processor is the amount of contact pressure applied between the mating surfaces. Compression will often times reduce the amount of thermal compound needed between the cooler and processor, and allow a much larger metal to metal contact area which is more efficient than having fluid weaken the thermal conductance. The greater the contact pressure between elements, the better it will conduct thermal (heat) energy.

Unfortunately, it is often times not possible to get optimal pressure onto the CPU simply because of poor mounting designs used by the cooler manufacturers. Most enthusiasts shriek at the thought of using the push-pin style clips found on Intel's stock LGA775 thermal cooling solution. Although this mounting system is acceptable, there is still plenty of room for improvement.

Generally speaking, you do not want an excessive amount of pressure onto the processor as damage may result. In some cases, such as Heat-pipe Direct Touch technology, the exposed copper rod has been pressed into the metal mounting base and then leveled flat by a grinder. Because of the copper rod walls are made considerably thinner by this process, using a bolt-through mounting system could actually cause heat-pipe rod warping. Improper installation not withstanding, it is more ideal to have a very strong mounting system such as those which use a back plate behind the motherboard and a spring-loaded fastening system for tightening. The Noctua NH-U12P is an excellent example of such a design.

In all of the tests which follow, it is important to note that our experiments focus on the spread pattern of thermal paste under acceptable pressure thresholds using either a push-pin style mounting system or spring-loaded clip system. In most situations your results will be different than our own, since higher compression would result in a larger spread pattern and less thermal paste used. The lesson learned here is that high compression between the two contact surfaces is better, so long as the elements can handle the added pressure without damaging the components.

Heatpipe Directional Orientation

Heat-pipe technology uses several methods to wick the cooling liquid away from the cold condensing end and return back towards the heated evaporative end. Sintered heatpipe rods help overcome Earth's gravitational pull and can return most fluid to its source, but the directional orientation of heatpipe rods can make a significant difference to overall cooling performance.

For the purpose of this article, all CPU-coolers have been orientated so that heatpipes span from front-to-rear with fans exhausting upward and not top-to-bottom with fans blowing towards the rear of the computer case. This removes much of the gravitational climb necessary for heatpipe fluid working to return to the heatsink base. In one specific example, the horizontally-mounted ProlimaTech Megahalems heatsink cooled to a temperature 3° better than when it was positioned vertically. While this difference may not be considered much to some people, hardcore enthusiasts will want to use every technique possible to reach the highest overclock possible.

Heatsink Test Methodology

Benchmark Reviews is obsessed with testing CPU coolers, as our Cooling Section has demonstrated over the past few years. We've solicited suggestions from the enthusiast community, and received guidance from some of the most technical overclockers on the planet. As a result, our testing methodology has changed with every new edition of our Best CPU Cooler Performance series. Because of this, each article is really its own stand-alone product, and cannot be fairly compared to the others. This particular article is a perfect example of that principle, since we're using a fresh methodology. Benchmark Reviews continues to test CPU coolers using the stock included fan (whenever applicable), and then replace it with a high-output fan for re-testing.

Manufacturers are not expected to enjoy this sort of comparison, since we level the playing field for all heatsinks by replacing their included fan with a common unit which is then used for every CPU cooler tested. Many manufacturers include fans with their heatsink products, but most 'stock' fans are high-RPM units that offer great airflow at the expense of obnoxiously loud noise levels. By using the same model of cooling fan throughout our heatsink tests, we can assure our results are comparable across the board. This is one of the more significant changes we have made to our test methodology, since many of the benchmark tests we have conducted in the past have compared the total package. Ultimately we're more interested in the discovering the best possible heatsink, and we believe that you'll feel the same way.

Testing was conducted in a loosely scientific manner. Ambient room temperature levels were maintained within one degree of fluctuation, and measured at static points beside the test equipment with a calibrated digital thermometer. Manufacturer-supplied thermal paste was not used in these tests, and a common Thermal Interface Material of our choosing (listed in the support equipment section below) was utilized instead. The processor received the same amount of thermal paste in every test, which covered the ICH with a thin nearly-transparent layer. The heatsink being tested was then laid down flat onto the CPU, and compressed to the motherboard using the supplied retaining mechanism. If the mounting mechanism used only two point of force, they were tightened in alternation; standard clip-style mounting with four securing points were compressed using the cross-over method. Once installed, the system was tested for a baseline reading prior to testing.

At the start of each test, the ambient room temperature was measured to track any fluctuation throughout the testing period. AIDA64 Extreme Edition was utilized to create 100% CPU-core loads and measure each individual processor core temperatures. It's important to note that software-based temperature reading reflects the thermal output as reported from the CPU to the BIOS. For this reason, it is critically important (for us) to use the exact same software and BIOS versions throughout the entire test cycle or the results will be incomparable. All of the units compared in our results were tested on the same motherboard using the same BIOS and software, with only the CPU-cooler product changing in each test. These readings are neither absolute nor calibrated, since every BIOS is programmed differently. Nevertheless, all results are still comparable and relative to each product in our test bed (see The Accuracy Myth section below).

Since our test processor report core temperatures as a whole number and not in fractions, all test results utilize AIDA64 to report averages (within the statistics panel), which gives us more precise readings. To further compensate for this, our tests were conducted several times after complete power down thermal cycles. Conversely, the ambient room temperature levels were all recorded and accurate to one-tenth of a degree Celsius at the time of data collection.

When each cooler is tested, Benchmark Reviews makes certain to keep the hardware settings identical across the test platform. This enables us to clearly compare the performance of each product under identical conditions. While the ambient room temperature did fluctuate between 23~24°C during testing, the thermal delta would not change enough to impact our test results. Benchmark Reviews reports the thermal difference in test result charts. For the purpose of this article, thermal difference (not the same as thermal delta) is calculated by subtracting the ambient room temperature from the recorded CPU temperature.

Intel Test System

• Processor: Intel Core i7-860 2.8 GHz (overclocked to 3.8 GHz @ 1.35V)
• Motherboard: ASUS Maximus III Formula (Intel P55-Express Chipset)

Support Equipment

• AIDA64 Extreme Edition 1.00.1111
• Zalman ZM-STG2 Thermal Grease
• Noctua 120x120x25mm fans (x2), model NF-P12 (54.3 CFM Advertised @ 19.8 dBA) 12V/0.09A

All of the tests in this article have been conducted using vertical motherboard orientation, positioned upright in a sealed traditional tower computer case (Corsair 700D). Heatsinks are positioned so that heat-pipe rods span horizontally, and described in our heat-pipe Directional Orientation from the previous section.

At the start of our test period, the test system is powered on and AIDA64 system stability tests are started with Stress CPU and Stress FPU options selected. For a minimum of thirty minutes (one hour) AIDA64 loads each CPU core to 100% usage, which drives the temperature to its highest point. Finally, once temperatures have sustained a plateau, the ending ambient room temperature and individual CPU core levels are recorded thus completing the first benchmark segment.

The second test segment involves removing the stock cooling fan (while the system is still under load) and replacing it with a high-output 120 mm cooling fan (if possible). The system is given thirty additional minutes with AIDA64 loading the CPU cores before final temperature readings are taken and recorded.

Editor's Note: There's a clear limiting in the tests with the Zalman CNPS9900, and that is that we can't switch fans in order to make different CFM tests. However, heatsink performance tests include the 135mm fan running at quiet mode, while high-output fan tests were conducted with the 135mm running at full speed. This only applies for the CNPS9900. All other heatsinks used the support equipment as described above as you can easily change/add fans to the rest of the contenders.

The Accuracy Myth

All modern processors incorporate an internal thermal diode that can be read by the motherboards' BIOS. While this diode and the motherboard are not calibrated and therefore may not display the actual true temperature, the degree of accuracy is constant. This means that if the diode reports 40°C when it's actually 43°C, then it will also report 60°C when it's truly 63°C. Since the design goal of any thermal solution is to keep the CPU core within allowable temperatures, a processor's internal diode is the most valid means of comparison between different heatsinks, or thermal compounds. The diode and motherboard may be incorrect by a small margin in relation to an actual calibrated temperature sensor, but they will be consistent in their margin of error every time.

Testing and Results

I used the following heat sinks in this comparison: Prolimatech Megashadow, Noctua NH-D14, Cogage Arrow (basically, it's the same as the Thermalright Silver Arrow) and of course, the Zalman CNPS9900 MAX. Many high-end heatsinks don't include a fan these days, so you need to pick up your favorite fans depending on your desired configuration. Since Zalman is using a 1500-1700 rpm fan, which at 1500rpm is quiet enough to be "silent", and 1700rpm is enough to be considered as high-output fan, I decided to use a pair of Noctua NF-P12 (rated at 54CFM) fans for comparison with the rest of the heatsinks. It's really difficult to compare 135mm fans, as many heatsinks don't even support that size, and while there are some heatsinks supporting 140mm fans, 120mm is still the standard. For these tests, I over-volted the Intel Core i7-860 processor to 1.350 volts, and overclocked it to 3.8GHz. RAM was running at 2400MHz all the time with a BCLK of 200MHz and 1.2 QPI voltage. The charts below report the thermal difference (processor temperature vs. ambient temperature) as well as the difference in degrees Celsius from the Zalman CNPS9900 MAX, in order of performance, with the best results listed first (lower is better).

Heatsink Performance Tests (Noctua NF-P12)

The CNPS9900 MAX did perform much better than I expected. I had to re-test 3 times in order to see if there wasn't a bug or a bad installation involved, but the results are OK. Against Noctua NF-P12 fans (silent setup), the Zalman CNPS9900 MAX performs very similar to the Prolimatech Megashadow with a dual fan configuration. It also surpasses the Cogage Arrow and any single heatsink setup, but it can't reach the Noctua NH-D14 with a dual fan configuration. Remember the CNPS9900 MAX is a semi-quiet heatsink working with a single 135mm fan, and for the price tag and Zalman's promises, you're receiving a very decent product.

Before all you start yelling at me, let me get this straight: The Zalman CNPS9900 MAX is a very decent cooler, and it performs very similar to other high-end heatsinks when used with quiet fans. That means if you're looking for a silent and smaller solution, and supposing you're not too extreme to change/add high-output noisy fans, then you should consider the CNPS9900 MAX as an option. This CPU cooler is NOT better than the rest of the coolers I tested for overclocking at "extreme" conditions, and the reasons are:

1. You can't install a second fan to improve airflow.
2. You can't change the fan for a high-output one.
3. It can't compete with higher TDP setups because of the reduced mass against other tower/dual-tower coolers.

Just to satisfy any person who will ask the conditions where the CNPS9900 MAX could be obliterated against the rest of the heatsinks tested today, I can say those conditions are pretty much anytime unless using stock fans or silent fans with moderated CPU load. Even if Zalman says this cooler supports up to 300w TDP, I'm sure the rest of the heatsinks will out-perform it thanks to their bigger mass. Also, you have the chance to add high-output fans and even install a second or a third (NH-D14 and Cogage Arrow) fan, improving performance in high-load tests. In conclusion, if you want a silent cooler for your moderated overclock setup, and you don't have a lot of space to install super-giant coolers with multiple fans, then choose the CNPS900 MAX. Otherwise, you should really try other options.

CPU Cooler Final Thoughts

Picking the right CPU cooler is rarely an easy choice, and Benchmark Reviews hopes we've made this process easier by providing information in this and other CPU cooler reviews. The market is changing rapidly enough that the top cooler of 2008 wouldn't be considered a serious contender in 2010; and manufacturers continue to asymptotically approach the theoretically ideal cooler than will bring your CPU down to ambient temperature. It's important to remember that there's a reason there are so many different coolers available: not every cooler works in every situation. The top-performing Prolimatech Megahalems is available at FrozenCPU for $61.99, and adding one or two fans can easily kick the total price over $80.00 (Zalman CNPS9900 MAX is priced at $79.99 at NewEgg store). Also, the Megahalems is a very large heatsink that may not fit in your system... and frankly it is overkill for all but the hottest, highest-clocked processors. The same applies for dual-tower heatsinks like the Cogage Arrow and Noctua's NH-D14 tested today. While low processor load temperatures are always good, reducing them another 5 degrees will make no difference to the stability or longevity of most systems (unless the load temperature is near the thermal limit of the CPU). The only reason you could want a super-heatsink would be for "extreme" overclocking sessions where 1-3 degrees could make the difference to break a score/record. If not, the Zalman could be an option, but there are some cheaper options out there performing similar. As always, it all depends on your needs.

The omega shaped heat-pipes and circular heatsink design isn't something you can find everywhere. The heatsink trend on 2010 is to add as many U-shaped heat-pipes on a single or dual tower heatsink and let the users decide the number and model of fans to install on it depending on their needs. Before jumping to the final conclusions, I'd like to add some scenarios where you could use the CNPS9900 MAX but won't be possible for many other heatsinks.

The first scenery is a micro-ATX or even Mini-ITX motherboard inside a small PC case. If you have enough room to add a full-tower heatsink you'll be very lucky, but it gets worse at the moment of adding fans. The Zalman CNPS9900 MAX will provide very decent cooling performance without the needs to add fans to the sides and it should be more than enough for Micro-ATX/Mini-ITX users. Also, thanks to its circular design, you can install any kind of high-profile RAM memory without worrying about CPU cooler clearance. I was impressed to see how much space left I had when pairing this cooler with the Patriot Viper II Sector 5 kit, because normally I have to struggle to fit my favorite coolers, or there's only 1 orientation possible (usually vertical)in order not to hinder RAM installation. Even if you had all your 4-6 slots filled with high-profile heatsink RAM, you shouldn't have problems with the CNPS9900 MAX.

The fan already allows PWM modulation so if you have a 4-pin motherboard connector, you should really take advantage of it to end with a very silent cooler. Let me add a personal note here. Zalman says its CNPS9900 MAX fan rotates at 900rpm at idle mode (PWM enabled) and it boosts up to 1700rpm at full load or 1500rpm with the RC7P resistor installed. However, when we asked for detailed information, Zalman told us the maximum airflow was 86CFM at 2000rpm. Why would we like to know a rated CFM at a speed their product can't even touch?

After that, when I started doing some tests, AIDA64 monitor reported 1950rpm at full speed (normal-operation mode). It was really, weird, so I monitored fan speeds within BIOS and other applications just to confirm numbers. The CNPS9900 MAX was running at 1100rpm at idle mode and PWM enabled (it should work at 900rpm). When the resistor was installed, it worked at 1700rpm (instead of 1500rpm), and at full speed, instead of running at 1700rpm, it almost reached 2000rpm (1950rpm to be precise). I feel like Zalman is hiding something here because at "2000rpm", the fan is loud enough to be considered noisy. Unless Zalman answers something else, or change their product specifications, I feel like they want to sell a silent product which is not silent at all, and which performs better than expected because of the extra air-flow, making reviewers and PC testers to build charts against lower-airflow fans, thus giving Zalman better results at the end. Of course, I'm considering they say there's a 10% error, so 1700rpm could mean 1870rpm, but going up to 2000rpm is suspicious enough, especially because the speeds are out of the margin and always tend to improve overall performance.

After all this drama, follow me to the next page where I express the final conclusions of the CNPS9900 MAX CPU cooler.

Zalman CNPS9900 MAX Conclusion

Please remember that these test results reflect our experience with each cooler on a specific motherboard, with a specific processor, BIOS revision, and test programs. That said, the ranking produced by these tests is accurate and gives a good idea how the coolers will perform relative to one another on any given system. Obviously, your choice of fans can dramatically affect the performance of any air cooler, but with the Zalman CNPS9900 MAX, you can't change or add extra fans.

Zalman's CNPS9900 MAX performance was better than I expected to be. While it can't compete with the best coolers in extreme conditions, it performs very similar to them when testing with silent fans. It only uses a 135mm fan, and it's good enough to give you a decent 24/7 overclock within good range, and without taking lots of space inside of your PC case. It looks like the 3 omega shaped heat-pipes really perform as 5-6 u-shaped heat-pipes, so I can't complain about the performance this time. If you're looking for a decent cooler with good performance the Zalman CNPS9900 MAX is an option to consider.

Appearance is a very subjective matter depending on the tasted of each person, but I think it's really difficult not to love this cooler because of its unique design. Instead of a full tower squared heatsink, we have a circular design with a very nice black-pearl finish and a LED fan. The LED isn't that bright, but the glow is enough to give a cool sensation about it. All the heatsink is black-painted, including the heat-pipes, the mirror finished base, and the fins, and more than 1 person will probably love to see it through your case's window to ask you which model is it and how does it performs.

Heatsink construction is quite good. The heatsink feels solid, and it's difficult to damage it because of the well-packaged box. However, here enters the point of the installation system, which is far from perfect. Installation is a real pain, especially if you're doing it inside the case with RAM, GPU or other components installed. Even outside of the case, you'll take some time to screw all the bolts with the provided bench. And if that wasn't hard enough, you can only install the heatsink 3 different times because Zalman included 3 sets of double-sided tape instead of providing a better cooler bracket installation method.

Functionality is good, but not perfect. While the CPU cooler provides great cooling performance even compared to some of the best heatsinks out there, there's no way to improve it more. You can't add a second fan, and you can't change the fan for a more powerful one. So, you're stuck with a 135mm fan which rotates up to 1900rpm (Zalman says 1700rpm), and nothing else. The good part is that the CNPS9900 MAX is smaller thanks to its circular design, and can bring good compatibility in smaller cases or in situations where a full tower heatsink wouldn't fit (high-profile RAM heatsinks or small motherboards).

As of November 2010, the CNPS9900 MAX costs $79.99 at NewEgg. You can get either the Blue LED or the red LED version for the same price. For its performance, I would think the cooler really fits in its category and price level, however, when we analyze functionality, and we notice that there's close to no improves available (you can't change/add fans) and the horrible (but solid) installation method, you'll feel like you shouldn't pay more than $65-$70 for this CPU Cooler. There are better options out there, but obviously they require more space, fans and noise.

So, if you're looking for a very decent and unique cooler for your PC, and you're not doing more than a moderated overclock or you need space to install RAM DIMMs or any other components, the Zalman CNPS9900 MAX could be a good choice. Otherwise, you'll be better with other heatsinks. The Prolimatech Megahalems is still one of the best coolers and you can install 2 fans on it depending on your needs. If you're looking for extreme coolers for massive overclocking, you should look for dual tower coolers like the Noctua NH-D14 and the Thermalright Silver Arrow, as they'll perform better with higher loads when paired with high-output fans.

Pros:

Cons:

Ratings:

• Performance: 9.00
• Appearance: 9.50
• Construction: 8.50
• Functionality: 9.00
• Value: 8.5

Final Score: 8.90 out of 10.

Quality Recognition: Benchmark Reviews Silver Tachometer Award.

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