Passive Cooling Solutions for Graphics Cards from Arctic Cooling and Cooler Master

We would like to introduce to you two great passive video card coolers from Arctic Cooling and CoolViva Z1 from Cooler Master that will be tested not only in passive mode but also with an additional cooling fan installed. The tests will be run on two different graphics cards: Nvidia GeForce 7600 GT 256MB and ATI Radeon X1950 GT 256MB.

by Sergey Lepilov
05/31/2007 | 05:29 PM

The idea of using passive cooling solutions for graphics cards is not a new one already, remember the Zalman ZM80D-HP passive cooler that wasn’t very efficient but absolutely noiseless (for details see our article called Zalman ZM80D-HP: Make Your Graphics Card Completely Noiseless). Developing the passive VGA cooling concept, the Accelero S1 and S2 solutions from Arctic Cooling that were first displayed at CES 2007 in Las Vegas have finally reached our lab. The cooling solutions from this manufacturer have always been very popular among overclockers, that is why today we are going to devote the entire review to them.


Besides, Cooler Master Company also was right in time with their new solution that will also participate in our today’s test session. It is the new CoolViva Z1. We have recently reviewed Cooler Master CoolViva Pro (for details see our article called New Graphics Card Cooling Solution from Cooler Master: CoolViva Pro Review) that left a very favorable impression and proved a pretty efficient and quiet solution. Since CoolViva Z1 is a passive cooler, we don’t doubt its noiselessness. However, as for efficiency and its ability to back up the good name of the Pro model, this is what our today’s test session is going to be about.

Testing Participants

Arctic Cooling Accelero S2

Although this solution features higher model number, S2, in its name, we are going to begin our discussion of this product family with this particular model, because it was the first one to hit the market, way before Accelero S1 did.

Not very big flat package made of transparent plastic allows you to take a closer look at the cooling system even before you make up your mind to buy it:

The front side of the square flyer lists the supported graphics cards, and the reverse side of it contains the main technical specs of the cooler and efficiency comparison charts. All accompanying accessories are stores in a small separate section inside the box:

Arctic Cooling Company positions its two cooler models for specific graphics cards only. The S2 model we are talking about right now is designed for graphics cards with not very high heat dissipation that is why it is built with only two copper heatpipes 6mm in diameter:

The heatpipes coming out of copper base go through 31 aluminum plates 188x18mm each. Therefore, the approximate area of the heat dissipating surface is The actual size of the Accelero S2 cooler is 140mm x 188mm x 32mm and its weight is only 202g.

The heatsink base is covered with a plastic cap protecting the pre-applied thermal grease from drying out. The thermal grease they use is the efficient ARCTIC MX-1 that takes about 8 days (200 hours) to stabilize:

Before installing this cooler on the graphics card, you have to remove the protective paper stickers from the aluminum sides of the cooler base and stick the corresponding plastic pads onto corresponding retention holes. These pads will protect the graphics chip from edge damage:

And then you have to fasten Accelero S2 cooler to the PCB with the accompanying screws and carton washer-pads from the bottom of the graphics card.

The passive heatsink installed onto a GeForce 7600 GT looks as follows:

A pretty massive-looking thing, isn’t it? But what is really important, despite the big size the heatsink is unusually lightweight. Accelero S2 is hanging about 4.5cm beyond the upper side of GeForce 7600 GT PCB, and about 1.5cm beyond the right side of it (note that these numbers may be different on other graphics cards).

Before you screw the heatsink to the graphics card, do not forget to put the aluminum heatsinks on top of the memory chips, because it will be a really hard task to complete once the cooler is installed.

There is at least 1.5cm if free room between the installed Accelero S2 cooelr and the GeForce 7600 GT textolite:

The last thing you have to do is to install two plastic locks that fit in-between the heatsink plates, catch onto the upper edge of the PCB and get locked with two special clips on the front side of the cooler. However, I didn’t do it, because I believe that very light weight of the cooler and reliable screw retention can hold the whole thing in place just fine. However, it is very nice to know that the manufacturer thought about it and offered this additional option.

Arctic Cooling also offers a special Turbo Module that consists of a plastic frame with a couple of 70-mm fans sitting on it. This module is intended to magically turn passive Accelero coolers into active ones that can cool not only the chip but the entire graphics card much more efficiently. According to the manufacturer, Turbo Module allows to reduce the chip temperature by about 14o C.

Unfortunately, this Turbo Module is not supplied with the new Accelero coolers and we didn’t get it in time for this tests session. However, we still managed to find an active cooling solution for our S1 and S2 models. It was a very simple and at the same time efficient choice: we installed a 120-mm fan on top of the heatsink:

Note that I simply tightened the fan diagonally to the cooler heatpipe on one side and plastic retention of the Accelero S2 cooler on the other side with plastic ties. This will do the trick as a temporary solution for our today’s test session, however, for more long-term use you will have to figure out something more reliable and long-lasting. I would also like to add that since our 120-mm fans is a pretty low-speed one (~1200rpm), we managed to keep our cooling system pretty low-noise.

This is what GeForce 7600 GT with installed Arctic Cooling Accelero S2 looks like inside a system case:

And in conclusion I would like to point out one more thing. Before installing Accelero S2 do not forget to put in a rear panel bracket with vent holes instead of the solid one that sits next to your graphics card. It will improve the removal of warm air from the system case (which is also true for the S1 model).

Accelero S2 cooling solution is currently selling for $22 USD.

Arctic Cooling Accelero S1

The top model, Accelero S1, comes in the same package as the S2. The information on the paper flyer inside the box is very similar, but the contents of the box is quite different.

The accompanying accessories also differ from those coming with Accelero S2:

Among the accessories are:

Accelero S1 is also built on a copper base, but there are 4 copper heatpipes instead of two coming out of it. Each heatpipe is 6mm in diameter:

Accelero S1 is a little bigger than S2: 140mm x 215mm x 32mm, that is why there are 32 aluminum plates, not 31 :)

The heat dissipating area is Despite larger dimensions, the cooler gained only a little bit of additional weight: it weighs 290g.

The heatsink base is larger, too, and is covered with ARCTIC MX-1 thermal grease:

As you can see, the retention mechanism is different from the one used on Accelero S2, so the S1 cooler fits on a smaller list of graphics cards. To be more exact, this cooler can only be installed onto AMD Radeon X1950, X1900, X1800 series and NVIDIA GeForce 7950, 7900, 7800, 6800 series solutions.

For our tests today we will use Radeon X1950 XT graphics card from Sapphire. This is what it looks like with Accelero S1 cooler installed:

And this is the same graphics card and cooler with the 120-mm fan attached to it the way we have already described above:

You can easily notice that the fan was shifted a little bit so that the airflow from it could also get to the PCB power elements.

Arctic Cooling Accelero S1 is selling for $29 USD. In conclusion I have to add that both S1 and S2 models come with 6-year manufacturer’s warranty.

Cooler Master CoolViva Z1

The next passive cooling solution for graphics cards we are going to talk about today comes from Cooler Master. Plastic package with a paper flyer designed in traditional Cooler Master color gamma inside and a ton of useful info on it are the typical traits this manufacturer’s products:

You can get a good look at the cooler from all angles even before you open the box. At the bottom of it there is a small paper box with accessories. These are not too numerous I should say:

Besides a large detailed assembly and installation guide in multiple languages, there is also a set of spring screws, Cooler Master sticker, four sticky round pads, eight aluminum heatsinks for the memory chips and a syringe with the company’s own thermal grease.

CoolViva Z1 boasts pretty original design and consists of two heatsink units connected with one another with a pair of copper nickel-plated heatpipes, each 6mm in diameter:

The heatpipes come out of the round copper base, approximately 4.5cm in diameter, which gets pressed against the graphics chip when the cooler is installed:

Beautiful heatsink over the copper base and heatpipes also takes some heat away from the GPU. However, the major heat load is removed via heatpipes to the second heatsink.

The inner side of the second heatsink is covered with thick protective film that prevents the heatsink from contacting with any electronic components on the reverse side of the graphics card PCB. If the gap between the heatsink and the graphics card PCB is big enough, you should better remove the film completely.

The cooler base is also protected with a plastic sticker against scratches and other physical damage. Although the base surface is not polished, the finish quality is very high:

The design of CoolViva Z1 implies that when installed onto the graphics card the second heatsink is beneath the graphics card and slightly shifted to the back edge of it:

On the photo above you can see CoolViva Z1 installed onto Radeon X1950 GT that is not listed among the supported graphics accelerators:

Nevertheless, we didn’t have any problems with installation. The procedure is very simple and intuitive that is why it doesn’t really make sense to describe it in detail here. Note that in case of Radeon X1950 GT the two heatpipes will go right above one of the graphics card memory chips, so you will not be able to top it with the aluminum heatsink included with the cooler.

The plastic frame on the second heatsink is removable, so you can install an 80-mm fan onto it, if necessary (the fan is not included with the cooler):

With the fan installed the cooling system looks like this:

Inside the system case (as well as in an open testbed) CoolViva Z1 will block the next mainboard slot. However, the rear heatsink with the fan on it will not be in the way of anything:

At the time of testing the price of this cooling solution wasn’t announced yet, but we believe it is going to be around $20, not more.


Now let’s sum up all the technical specifications of our testing participants in a single table for your convenience:

Testbed and Methods

The tests of all cooling solutions were performed in a closed system case only in identical testing conditions. The testbed was built with the following hardware:

The tests are performed in Windows XP Professional Edition SP2 operating system. We used DirectX 9.0c (released April 2007), ForceWare 93.71 and Catalyst 7.2 graphics card drivers. The graphics cards were warmed up by running the Firefly Forest test from the synthetic 3DMark 2006 benchmarking suite with disabled anisotropic filtering and anti-aliasing.

The graphics cards temperatures were monitored with RivaTuner version 2.1 utility. Each cooler was tested at least two times with a stabilization period of 13-15 minutes between test cycles. If the results obtained in a repeated test were more than 2o C different from the previous ones, the tests were performed again until we got fine precision results. The room temperature during this tests session was relatively low: 21o C.

The average fan rotation speed of all testing participants in different modes is listed according to the monitoring data, and not according to their default specs. Default graphics card cooling solutions are marked as “Stock cooler” on the diagrams below. I would like to remind you that Sysconn GeForce 7600 GT graphics card comes equipped with a non-default cooling solution that looks very much like an all-aluminum Zalman VF700. As for sapphire Radeon X1950 GT, it comes with a pretty typical cooler for graphics cards of this type: a single-slot solution with a fan and a copper ribbed heatsink:

In Auto mode under 3D workload the fan runs at 80% of its potential and is very loud. At 100% the noise is simply unbearable. The system can be considered quiet at 40% of the fan speed that is why besides the thermal measurements at maximum fan rotation speed, we have also included the results at 40% of fan rotation speed.

Besides the default graphics card cooling solutions we have also included the results of Zalman VF900-Cu LED cooler on copper heatpipes. It operates in quiet mode at 1380rpm. Arctic Cooling Accelero S1 and S2 coolers were tested in passive mode and with one 120-mm fan from Scythe (20.9dBA, 49.6CFM). Cooler Master CoolViva Z1 was also tested in passive mode and with one 80-mm Cooler Master fan (2000rpm) installed. It is not a noiseless mode, of course, but the fan is very quiet overall.

Thermal Performance

Let’s take a look at the results:

At first I would like to say a few words about the results obtained with overclocked GeForce 7600 GT. As you know, this graphics card dissipates not too much heat, and the results show that both, Accelero S2 as well as CoolViva Z1 both do very well with it, the latter is even 1o C more efficient. Without additional fans installed both cooling solutions lose about 7-8o C to the well-known Zalman VF900-Cu LED, but the moment you put the fans on them, both our heroes leave no chances to their competitors. Look at the GPU temperature difference under peak workload: Accelero S2 and CoolViva Z1 cool the graphics chip by about 10o C more efficiently than the standard Zalman VF900-Cu LED. Overall, the chip temperature is very low and I wish it had a positive effect on the overclocking results. Running a little bit ahead, I would like to say that even the graphics processor of the GeForce 8600 GT graphics card cooled with Accelero S2 cooling solution didn’t heat up to 41o C. Excellent results!

Even more impressive results were obtained with a relatively warm overclocked Radeon X1950 GT. As you can see from the design of the stock cooling solution, it is no good for this graphics card. However, how surprised we were when it turned out that Accelero S1 in passive mode cooled this graphics chip better than the stock cooler with its fan running at maximum rotation speed! Unfortunately, CoolViva Z1 cannot boast the same impressive efficiency in passive mode, as the graphics chip gets really hot in this case. However, an 80-mm fan on the lower heatsink of this cooler resolved the issue completely and pushes the temperature 40o C down! This is excellent proof that I shouldn’t have had any concerns about the original design of CoolViva Z1: it works perfectly fine. Accelero S1 and CoolViva Z1 in active mode prove more efficient than Zalman VF900-Cu LED by 14.5o C and 10o C respectively. Moreover, with these two coolers I managed to push the frequency of my Radeon X1950 GT to 688MHz without any stability issues. And the temperature hardly rose at all in this case: by about 1-1.5o C.

In addition I would also like to offer the diagram with Radeon X1950 GT PCB temperature:

It is quite logical that in passive mode both new cooling systems cannot catch up with the competitors, because there is no airflow to cool down the PCB components. However, the temperature is not critical at all under both: Accelero S1 as well as CoolViva Z1. Once the fans are installed the situation improves, although I have to admit that the front 120-mm fan of Accelero S1 makes it more efficient than CoolViva Z1.


I would like to point out right away that we liked very much all cooling systems discussed in this article. Both Arctic Cooling solutions proved up to the mark and performed perfect according to their positioning and range of supported graphics cards. The same is true for Cooler Master CoolViva Z1, but for “graphics cards with low heat dissipation”. Yes, this cooler can also cope with an overclocked Radeon X1950 GT, but the GPU temperature is too high in this case, in my opinion. However, an additional fan installed on top of the lower heatsink makes CoolViva Z1 a very efficient cooler. Accelero S1 and S2 are even more efficient with an additional 120-mm fan – in this case they are truly the best graphics card coolers out there. I hope that the recommended Turbo Module will also prove a great addition to them.

I tried to find some drawbacks about the three cooling solutions reviewed today, but couldn’t. They block the slot next to PCI Express? – Come on, most of the graphics cards in the market are already bundled with a dual-slot cooling system anyway, and third-party coolers no longer feature single-slot design either. They are pretty large? – Yes, they aren’t small, but that will hardly cause any problems. Arctic Cooling Accelero coolers are not universal? – No, but there are two of them available. Price? – The price is pretty competitive in this market segment and Zalman VF900-Cu LED costs $20 more. So, it should be more than enough to buy the whole bunch of additional fans :), and one high-quality fan for CoolViva Z1 costs only $2.5-$3.

So, feel free to pick one, all three of them are going to prove an excellent choice!