It has been already some time, that Arctic Cooling has announced new passive cooling solution for high-end graphic cards. This set off a heated discussion among all enthusiasts supporting powerful but silent approach. This debate opened up a question, if Accelero-S1 and Accelero-S2 are able to challenge today’s very successful high quality cooling performers. The most serious rival competitor Thermalright HR-03, primary designed for passive cooling, has been already discussed. Thermalright HR-03, “the King among VGA coolers” has been on market for a while to prove its qualities. Today’s detail roundup will compare its abilities against Accelero-S1. Than there are Zalman VF900-Cu and Zerotherm GX815, other two high-end active VGA coolers to compete, primary with their passive cooling properties.

Accelero S1, designed for high-end graphic cards and the higher ranked of two arctic cooling brothers, is coming on our market little bit sooner than Accelero S2, which is specified to be more for main stream graphic cards. Unreasonably lots of time passed since Arctic Cooling has announced development of three passive coolers. At the end, after lengthy trials, two versions have been released: S1 and S2. Features of version S3 - originally considered to be designed for ATI X1300, X1600 and nVidia 7600 graphic cards, have been virtually implicated in S2. Version S2, meant to be made exclusively for nVidia 7800 GS (AGP) was not launched at the end. Its compatibility has been involved into S1 model.
We can only doubt about reasons, which retarded release of Arctic’s passive cooling solution. Obviously, it was producer who was loosing as in a meantime; market has been flooded with other not as effective products, sometimes with not reasonable prices. But now there is Accelero S1, and that is important for all users. Let’s present this cooling performer now…

Who is waiting any revolutionary change in packaging of new passive Accelero, has wrong expectations. Arctic Cooling keeps its standard and Accelero comes as usual in a plastic transparent case with classic black flat card placed inside, which includes all the information about product’s main features. Like that, potential user can immediately see what does product look like, as cooler as well as its accessories are clearly visible.

Short glimpse at the backside of a housing, and it is clear on the first sight, that there is something wrong. There is an empty place, where was supposed to be a module, made for cooling of voltage converters for graphic cards ATI X1950Pro. This module differs in a shape of MOSFET passive, designed for other compatible graphic cards with S unit. Not even the producer was able to explain its absence in the packaging, mentioning this passive as part of a pack on its official pages. For many owners of an X1950Pro, MOFSET would be unnecessary anyway. We explain this downside with bad expeditionary coordination. Like that, passive S1 used in this test was taken from a previous batch. Positive message for a future is, that in the next delivery, housing is going to be complete.

Let’s take a look at each feature in packaging individually. Besides passive cooler for graphic cards, there are eight little aluminium heatsinks and two bigger aluminium heatsinks for voltage regulator components. One is for ATI X1800, X1900 and X1950XT,XTX cards and second would be for X1950Pro, but is missing in a pack. In a plastic housing, there is set of all the necessary screws with washers and plastic catch holders, for better connection of S1 passive with graphic card. Than there are perforated PCI blind flage, Arctic Cooling logo sticker, and obligatory step-by-step installation manual written in four languages.

From technical specifications it is clear, that Accelero S1 is a notable contender, what is no surprise, regarding its passive method of cooling designed for highest performance graphics. This time, Arctic Cooling made kind of Jumbo fan, which should be able to carry off the huge amount of thermal energy from graphic chips.

There is also another difference from official packaging presented on web sides of Arctic Cooling, which I would like to put into your attention. It seems to be only design thing, but anyway, one more time Arctic Cooling is loosing a credit. There are two Accelero S1 logo stickers missing on black plastic ending parts, framing the aluminium plates from two sides. But this imperfection, together with missing MOSFET for X1950Pro is only a first distribution’s downside and future owners, do not have to worry any more.

I have to admit, that Accelero S1 is a jewel, regarding its design and construction. Designers took their time, and the final construction is made with the aim to maximally utilize the potential of a cooler. Single aluminium plates are placed just in a right distance, and heat-pipes have no chance to affect each other. Dissipating surface is above all standards; its size 2750 sq.cm is unique, nevertheless with the height 32 mm, S-unit does not differ from another coolers. This cooler uses its giant surface 215X140 mm and 32 aluminium plates for very efficient heat dissipation.

The heatsink base, the heart of a cooler, is separately protected with transparent plastic case. This is to protect the thermal grease, applied by a producer, which is covering and protecting the base against abrasion. Pre-applied thermal grease has become an Arctic Cooling standard; even there are doubts about its advantages and disadvantages. For certain group of users, who after placing the cooler on a place do not manipulate with it any more, it can be a convenient solution. They do not have to take care about applying of the thermal paste on a base. But I would say that for users working with their hardware more often, the separate pack of thermal paste, serving for multiple installation of cooler, would be more suitable.

Elaboration of the copper base is not really supreme. The cover is quite rough, and it seems that manufacturers did not really care about finishing works, like fine grounding. Actually, this has become also kind of standard of this Swiss producer. But let’s say, very reasonable price-quality rate has to be expressed somewhere. In a contrast with quality of base surface, thermal paste is still applied very precisely. There is a very fine grey film of paste covering the bigger part of contact surface of a base. From a structure of surface, it is clear that Arctic Cooling did not use quite hard thermal interface MX-1, as usual, during the pre-applications. Paste consistency proves it, as it is soft and supple.

The other side of a base, serving like an assembling console for attaching the cooler together with graphic card, is designed very sophistically. Harmonious shapes, pleasant surface, nicely looking Arctic Cooling logo do not contribute to cooler’s functionality, but are anyway positive side of the heatsink base.

Space between two parts of a base is filled with four heat-pipes, tightly soldered up together. There are traces of tin, in places where pipes and a surface are attached, clearly visible. But there is not any abundance of material on a place, and the construction keeps high standard.

There are heat-pipes coming out from a base dividing upon the plating. Before connecting with aluminium fins, pipes are bent on two places into a right-angel. All is made technically on a very high level and deformations from inner side are minor, and that is not even common for the other hot and prestigious cooler’s manufacturers.

Optimized heat pipes design is an important factor affecting overall effectivity of cooler. The Accelero S1 is bright example, as its heat pipes are shifted just in a right distance. Pipes totally exploit 215 mm length of a passive cooler. On the other hand, there are some imperfections visible, on places where heat-pipes are connected with fins. Press working without any welding is already quite rare to find. Well, that is probably only another little imperfection allowing the Accelero S1 to be available for a bargain prize.

The shortcomings are visible mostly in places where the heat-pipes are attached to the fins. Minimal impact or small pressure is enough to cause shedding of plates. But this should be nothing to be aware of, as fins do not tend to detach spontaneously, only rough handling can cause falling off. What is more, there are two black plastic framings from both sides of cooler, strengthening all the construction.

The installation of Accelero S1 on the graphic card should be very easy, just few steps to follow, described in detailed step-by-step installation manual. Knowledge of any foreign language is not necessary. Even less skilled user, should be able to understand installation process looking at the pictures in manual. In the first step you have to screw the passive cooler to the voltage regulator module (valid for ATI), and after that you stick little passives on a memory chip. The last think you have to do is to fasten S-unit on a graphic chip using four screws and plastic locks for better fixation.

The passive Accelero S1 installed onto ATI X1800GTO2, which I used for a test, evidently looks good. Here you can see how massive the cooler is, hanging beyond the both sides of graphic card, what is especially visible on the opposite side of the base.

…as only four screws are needed to secure the Accelero on a graphic card, for better fixation, with the cooler hanging off the card because of its dimension, there are two more plastic locks to support onto the edge of a graphic chip.

The whole process of installation is very simple; nevertheless you will probably face few unpleasant surprises, which will extend all the setting. First frustration will regard those owners of ATI graphic cards, who will decide to change original smaller MOSFET passive with the bigger one, enclosed with Accelero. In one of two outer parts of a cooler, in places where voltage regulator is supposed to fit with a graphic card components, it seems that in Arctic Cooling, they did not really pay attention to how much of free space is needed. Therefore it is necessary to finely grind down the aluminium passive in this place in order to avoid a little collision and to accommodate the heat spreader. Then you just fix the passive cooler with two screws.

I guess, also installations of individual little RAM heatsinks will probably slightly higher your adrenalin. One would not ever say that applied thermal tape is holding a brand 3M. According to data on a producer’s pages, this should be a product belonging to a “200MP High Pref” group. Very precisely “467MP” type, with a thermal endurance up to 232oC. That sounds great, but the thing is that thermal tapes do not stick very well at all, and little passives do not stay on a heatsink. Some of them fell right off immediately, and that is not acceptable.
Like that your enthusiasm changes into a frustration. At the end, I found necessary to buy my already proved 3M thermal tapes, and change the tape on each of little RAM heatsinks.

After all the initial troubles, installation of Accelero S1 itself is a very simple task. Just like written in a manual, all the process is very easy. Thermal paste is already applied; you just place the base onto a graphic card, and only four screws and two plastic locks are needed to secure it. Than the graphic card is ready to use.

Nobody can probably resist, trying the new Accelero S1 with subsidiary more powerful airflow, despite the fact that this cooler provides completely passive cooling, and any components allowing extra fan fixation are not available. But do not be afraid of this idea. The problem how to secure additional fan, is actually very easy to resolve, without spending much time and energy.
To get as much data as possible in this review, we have tested not only the passive cooling abilities of the S-unit, but we also made the power test with some different installed fans. The Accelero S1 is, as mentioned above, the cooler of massive dimensions, to make the best of it, we tried to use two fans instead of one. Looking at the following pictures you can see how two 92 mm fans seem to be lost on a heatsink.

So not even two 92 mm fans are able to fulfil the surface of the heatsink. There is still plenty of space on lateral sides, without a direct support of air fluctuation. It seems obvious, that one fan placed on a heatsink would be completely lost, but evidently it would not influence its effectiveness at cooling. Even one extra fan, should effect the overall passive potential of a cooler. Both options will be described in details in this roundup.

Even more attractive would be using of 120 mm fans, providing low noise cooling, also at higher airflow. And we cannot miss this very interesting alteration in today’s test. Like that S-unit will enjoy the performance with one and two fans, respectively. Following pictures are proving that Accelero S1 is perfectly designed for two 120 mm fans.

The fact that Arctic Cooling does not provide plastic locks for a 120 mm fans fixation, I consider like a vasting of a cooling potential. This cooler really seems to be just made for two120 mm fans. And I guess this setting will be the most interesting in this roundup…
...but you will find more in the results.