0 Degrees Centigrade: APACK ZEROtherm CPU Coolers Roundup

We are going to introduce to you a family of processor cooling solutions from APACK Company known under ZEROtherm brand. Among 5 models participating in our today’s roundup you will meet a new ultimate performance leader!

by Sergey Lepilov
04/03/2008 | 01:32 PM

In our recent review devoted to graphics card coolers we promised to introduce to you a variety of cooling solutions for CPUs from the Korean APACK Company (for details see our article called Two New Coolers for Nvidia GeForce 8800 GTX or Minus 20 Degrees for the Reference). Well, it is time we kept that promise. So today we are proud to offer you a roundup of five ZEROtherm processor coolers designed for overclocked CPUs.


ZEROtherm coolers that we have already used a few times in our lab testbeds for other reviews have aroused quite some interest among overclockers. So we decided to make up for the lack of information on these solutions on our site. Let’s get started!

ZEROtherm BTF80, BTF90 and BTF92 O.E.

In this chapter of our roundup we are going to talk about three APACK ZEROtherm cooling solutions at a time, because they are all very similar to one another in terms of design. Tow models – ZEROtherm BTF80 and ZEROtherm BTF90 – are practically identical twins, differing only by the material used for heatsink plates: BTF80 has aluminum heatsink, while BTF90 – copper heatsink. So, we are going to discuss both of them using BTF80 as an example.

BTF92 O.E., however, looks similar to the other two, but is still pretty different in its design.

Package and Accessories

As usual, let’s first take a look at the coolers packaging.

The boxes are designed in silver gamma and are made of thick cardboard with plastic carry handles at the top. There are cut-out windows on the front and back of the boxes that let you pick at the cooler fan and partially heatsink:


Besides the list of cooler key features on the front of the box, there is also some info on the supported socket types. The sides and back of the cooler packages bear some technical specifications and performance diagrams comparing these cooling solutions against the competitors’ products, although there is no mention which these are:


According to the package, the coolers are made in Korea.

In the upper part of the package there is a small cardboard box with the bundled accessories:

It contains a standard accessories set for each cooler that includes the following items:

Besides, the BTF92 O.E. is also bundled with a fan rotation speed controller and four adhesive pads for placing it inside the system case:

Design and Functionality

The coolers look very beautiful. See for yourselves:


The design of BTF80/90 and BTF92 O.E. is identical. All these coolers are based on four copper heatpipes 6mm in diameter, each originating from the copper base, looping through the copper or aluminum heatsink array and ending in the same copper base again:


BTF80/90 are of the same size and measure 100mm x 94mm x 77mm. They weigh 458g and 678g respectively. BTF92 O.E. is a little larger: 108mm x 81mm x 128mm and weighs 638g.


However, the coolers differ not only by their size and weight. The thing is that despite smaller size, BTF80/90 models have 46 heatsink plates, while BTF92 O.E. model has 5 less – only 41 plates. As a result, the heat dissipating area of the BTF80/90 coolers is claimed to be 4,400cm2, while that of the BTF92 O.E. is smaller and equals only 3,624cm2.

The BTF80/90 plates density is also higher (the gap between the heatsink plates is smaller):


If you look at the top part of both coolers, you will see that the stamped heatsink plates are of identical shape, and with the plastic insert in the center they even look like a butterfly:


I wonder what’s the purpose of those different diameter holes at the end of the plates where the airflow comes out? Looks like these are purely decorative elements. I doubt that they affect the airflow turbulence in this area or in any way reduce the level of generated noise.

The heatsinks are cooled with 92x25mm fans that are attached on a removable plastic stand:

BTF80/90 models use the same fan with PWM (Pulse-Width Modulation) rotation speed control option. So, the fan rotation speed is automatically adjusted in the interval between 750 and 2,500RPM (±10%) with the maximum level of noise at 27dBA and 42.8CFM airflow. BTF92 O.E. cooler got this “O.E. - Overclocker Edition” addition to its name not only due to larger size but also to the use of an advanced fan (as the manufacturer claims). Its rotation speed can be adjusted from 1,000 to 2,300RPM (±10%) thanks to the rotation speed controller bundled with the cooler. In reality the maximum fan rotation speed is much higher than the 2,300RPM claimed in the specifications. The fan can speed up to ~3,060RPM.

The base of both coolers is covered with transparent plastic film to protect the copper surface against scratches and other unpleasant incidents:


And there is a lot to protect here, believe me. The base is impeccably even and features remarkable mirror-shining polish:

Now I have to say a few words about the heatpipes in the heatsink base. First of all, they are arranged not linearly but alternate in pairs to ensure better distribution of the heat flow over the heatsink plate array:

Secondly, each cooler has four heatpipes, as you remember, but each heatpipes originates from the base and then returns to the same base after looping through the heatsink array:

In other words, the copper plate in the cooler base contacts eight heatpipes at once, which we haven’t ever seen before (the maximum number of heatpipes in the base we saw was 6). Here I would also like to add that each heatpipes sits in a special groove. Each heatpipe is soldered to the base. I also have to stress that the cooler is put together in a very high-quality way, features very reliable design and secure contacts between its elements.

Installation Tips

All three ZEROtherm cooler models we have just discussed can be installed with one of the two available retention sets, which should first be attached with four screws to the cooler base:


To install the coolers on mainboards for AMD K8/K10 processors, you don’t need to remove the board from the system case, because the cooler retention clips to the standard plastic frame on the front of the mainboard PCB. However in case of an LGA 775 system, the cooler retention goes through the PCB and screws on to the backplate on the other side of it. It is interesting that you will have to remove the plastic insert with the fan before installing the cooler, because otherwise you will not be able to tighten the screws on one side of the cooler:

The backplate has adhesive padding around the center of it. so the first thing you do, is stick the backplate to the bottom of the mainboard PCB, then install the cooler and then tighten the screws to the backplate:

All three cooler models are pretty compact at the base, so they will not conflict with any electronic components around the processor socket or tall chipset heatsinks as well as voltage regulator elements:

Moreover, each cooler looks very compact when installed into a system case:


They also make a very pleasing sight:


Besides, the aluminum cooler model features a fan with red LED highlighting, while the copper models – a fan with blue LED highlighting:


Taking into account the current discounts the coolers are priced at $30.99 for the BTF80 model, $31.99 for the BTF90 model, and $35.99 for the BTF92 O.E. model.

ZEROtherm BTF95 Fanless

Package and Accessories

The next solution stands out in the ZEROtherm cooler lineup, although it ships in a similar looking silver package:


The accessories are packed into the same cardboard box sitting at the top of the package. The included items are pretty much the same as those of the previously discussed models:

Of course, the cooler name and the corresponding message on the box suggest that ZEROtherm BTF95 Fanless is a passive cooling solution, i.e. a cooler without a fan.

Design and Functionality

Let’s take a closer look at this cooler:

The heatsink is of very beautiful shape. It is designed the same way as those of the previously discussed systems. However, it features fewer copper plates in the heatsink array: only 32. Therefore, the gap between the plates is a little bigger:

This change in the design is quite logical, because without a fan the heatsink plates will only be cooled with the airflow generated by the case fans, if there are any in your system.

And while the butterfly-shaped heatsink wasn’t really a key distinguishing feature of the previous three CPU coolers, it definitely is one by ZEROtherm BTF95 Fanless.

Otherwise, the cooler is exactly the same as BTF92 O.E.: the same size, shape, number of heatpipes and base finish quality:

It weights a little less than BTF92 O.E.: only 510g.

Installation Tips

The cooler retention is of exactly the same type as those of the other three models. So, before the actual installation you should attach one of the two available brackets to the base of the cooler exactly the same way as described above.

Since these seem to be all the distinguishing features of ZEROtherm BTF95 Fanless and inside a system case it looks just a little bit different from the previous models, there is not much left to discuss. I would only like to add that its recommended price is set at $33.99.

ZEROtherm Nirvana NV120 Premium

And finally we would like to introduce to you the flagship product from APACK ZEROtherm cooler family - ZEROtherm Nirvana NV120 Premium.

Package and Accessories

The cooler arrived in a silver box with a little bit different decorative design:


Besides the cooler name on the front side of the box, there are original pictograms that depict its features. The back of the box lists the technical specifications of the cooler in ZEROtherm’s traditional way and bears a photograph of the solution.

Inside the cardboard box there is a robust plastic casing that holds Nirvana NV120 Premium cooler. The casing consists of two sections:

One for the cooler itself and another one for accessories:

The cooler is also made in Korea, like all the other today’s testing participants.

Design and Functionality

I believe the cooler is extremely beautiful:

The massive heatsink of Nirvana NV120 Premium cooler consists of 41 aluminum plates, each about 0.3mm thick. The plates painted with dark-gray glossy paint sit on four copper heatpipes, each 6mm in diameter. The whole heatsink array measures 128 x 95 x 150mm and is cooled with a 120 x 25mm fan:

One of the peculiarities of this top of the line cooling solution from ZEROtherm is non-linear positioning of the heatsink plates in the middle of the array that the manufacturer refers to as “honeycomb structure”.

According to APACK ZEROtherm engineers, these intersecting plates increase the airflow turbulence and thus improve the cooling efficiency.

The sides of Nirvana NV120 Premium cooler are not covered with any panels, so unfortunately, some of the airflow gets wasted:

Here you should note that heatpipes originating from the cooler base are directed slightly sideways, which allows to distribute the heat more evenly over the heatsink plates:

Speaking of the cooler base I have to specifically point out how well the heatpipes are connected to the copper base plate. The heatpipes are soldered to the base and not glued with thermal adhesive, which is often the case with other coolers out there:

The base sole is finished quite nicely, even though we can see radial mechanical tool marks:

The surface is very even, which we double-checked using our traditional thermal compound imprint method on the glass surface.

Installation Tips

The cooler installs in exactly the same manner as the other four ZEROtherm models we have already talked about in this article. First you need to pick one of the two available retention brackets and attach them to the base of Nirvana NV120 Premium cooler with the bundled screws:


Both types of retention press 638g of Nirvana securely to the CPU heat-spreaders. If the cooler needs to be installed onto an LGA 775 mainboard, it may be tricky to tighten the screws on the same side as the fan. In this case you will need a long screw-driver, because the fan blades are right above the screws and I couldn’t figure out a way to remove the fan.

When the whole thing is inside the system case already, the cooler doesn’t get in the way of chipset heatsinks as well as mainboard voltage regulator components it will also coexist just fine with tall memory heat-spreaders:


And two blue LEDs highlighting the working fan will definitely be a pleasing sight for modding fans:

This beauty is priced at $39.99. Without the discounts and rebates the cooler would sell for $59.90.

Technical Specifications

The detailed technical specifications and recommended retail price of the coolers we have just discussed are summed up in the table below for your convenience:

* - according to test results.

Testbed and Methods

All ZEROtherm coolers we discussed today and their only competitor in this test session were tested in two modes: in an open testbed when the mainboard sits horizontally on the desk and the coolers are installed vertically, and in a closed testbed with the mainboard in vertical position

We put together the following testbed for our experiments:

Using the weakest cooling system of our today’s testing participants we managed to overclock our quad-core processor to 4GHz with the Vcore increased to 1.6V in the mainboard BIOS. The monitoring utility reported the core voltage setting a little bit lower than what was set in the mainboard BIOS: around 1.575~1.6V. The system memory was working at 1066MHz efficient frequency with 5-5-5-16_2T timings and 2.05V voltage.

All tests were performed under Windows XP Professional Edition SP2. SpeedFan 4.34 Beta 38 was used to monitor the temperature of the CPU, reading it directly from the CPU core sensor:

Its readings matched those of the Core Temp 0.96.1 utility:

The mainboard’s automatic fan speed management feature was disabled for the time of the tests in the mainboard BIOS. The CPU thermal throttling was controlled with the new RightMark CPU Clock Utility version 2.35.0 that now supports Intel Core 2 Extreme QX9650 processor.

The CPU was heated up with OCCT (OverClock Checking Tool) version 1.1.1b in a 23-minute test with maximum CPU utilization, during which the system remained idle in the first and last 4 minutes of the test:

I performed at least two cycles of tests and waited for approximately 20 minutes for the temperature inside the system case to stabilize during each test cycle. The stabilization period in an open testbed took about half the time. The maximum temperature of the hottest CPU core of the four in the two test cycles was considered the final result (if the difference was no bigger than 1°C – otherwise the test was performed at least once again). Despite the stabilization period, the result of the second test cycle was usually 0.5-1°C higher.

The ambient temperature was checked with an electronic thermometer that allows monitoring the temperature changes over the past 6 hours. During our test session room temperatures varied between 24.5 ~ 25°C. It is used as a staring point on the diagrams. Note that the fan rotation speeds as shown in the diagrams are the average readings reported by SpeedFan, and not the official claimed fan specifications.

The noise level of each cooler was measured according to our traditional method described in the previous articles with the help of an electronic noise meter – CENTER-321. The subjectively comfortable noise level was considered 34.5dBA and is marked with a dotted line in the diagram. The ambient noise from the system case without the CPU cooler didn’t exceed 33.2dBA when measured at 1m distance.

We didn’t choose the competitor for APACK ZEROtherm coolers basing on their price point. We simply decided to compare them against Thermalright Ultra-120 eXtreme super-cooler equipped with Scythe Minebea 120x120x25mm fan rotating at ~1940RPM (according to the monitoring utilities) and at ~1190RPM in its quiet mode. I believe that since the price of ZEROtherm coolers is not that much different overall, this will be more than enough to rank the coolers within the lineup and compare against one of the today’s best cooling solutions available.

Cooling Efficiency and Acoustic Performance

Cooling Efficiency Tests

The coolers on the diagrams below are listed in practically the same order as we have been discussing them today. The results are the following:

First of all I have to point out minimal difference in CPU temperature with the aluminum ZEROtherm BTF80 and copper BTF90 models. Looks like the heatsink design turned out so efficient that replacing the aluminum plates with copper didn’t really improve that much, so I believe it doesn’t make much sense to pay extra for a heavier cooler.

The next one in the ranks is the overclocker model called ZEROtherm BTF92 O.E. Don’t be surprised that it lost to the previous two models here in quiet fan mode, because the other two models have fans supporting PWM and hence have about ~1,000RPM advantage. However, once the fan of the BTF92 O.E. speeds up, the cooler easily outperforms the two younger brothers getting about 3-4ºC ahead of them in peak temperature.

However, we were really impressed with the performance of the top model - ZEROtherm Nirvana NV120 Premium. It is quite logical that this cooler demonstrated better efficiency than the previous three solutions from APACK and we had actually expected it to. However, we were very pleasantly surprised to see that Nirvana NV120 Premium was at least as efficient as Thermalright Ultra-120 eXtreme super-cooler with high-quality Scythe fan. So, we can state with all certainty that overclocking fans just got another super-cooler to consider.

You don’t see the results of ZEROtherm BTF95 Fanless on the diagram, do you? True, because the passive solutions cannot cope with cooling a quad-core processor overclocked to 4GHz frequency. This is not surprising at all, as BTF95 Fanless was not designed for that. However, it will do perfectly fine with cooling an Intel Core 2 Extreme QX9650 processor working at its nominal speed. It will maintain its temperature at steady 68ºC under maximum workload in a well-ventilated closed system case:

Click to enlarge

In fact, you can even overclock this quad-core processor a little bit with ZEROtherm BTF95 Fanless cooler: to 3.41GHz by raising the Vcore to 1.325V. In this case the hottest core under maximum workload will heat up to 88ºC (and looks like there is still way to go further):

Click to enlarge

All in all, this is a very good result for a cooling solution like that, I should say.

Acoustic Tests

We measured the level of noise generated by our today’s testing participants from a 3cm, 1m and 3m distance. The results are given on the diagram below:

The results are quite logical and speak for themselves. There is nothing I can actually add here.


Our today’s tests showed that there is at least one more very serious brand name in the cooling solutions market these days – APACK ZEROtherm. A pretty diverse lineup of their cooling solutions we have tested so far made a highly favorable impression. They are offering a great option for night-time internet surfers, who care about the level of generated noise a lot: BTF95 fanless. There are three models for overclocking fans who care about the exterior looks as much as about the cooling efficiency – BTF80/90 and BTF92 O.E.

But I would like to specifically point out a remarkable performance of ZEROtherm Nirvana NV120 Premium – cooler with only four 6-mm heatpipes that managed to demonstrate the same cooling efficiency as Thermalright Ultra-120 eXtreme that has remained undefeated for quite some time now with very few exceptions. I couldn’t find any drawbacks in the design or performance of the ZEROtherm Nirvana NV120 Premium cooler so all I can tell APACK engineers is to keep up the great job and continue pleasing us with impressive processor and graphics card coolers in the future.

Summing up the results of our test session we decided to award ZEROtherm Nirvana NV120 Premium with our prestigious Editor’s Choice title as the best processor air cooler with heatpipe technology.