This week we have taken two very highly rated air cooling systems for graphics and put them to the test up against a stock cooling unit. The graphics card in questing being the mighty Sapphire ATI X1900XT 512. The coolers that were put to the test along with the stock cooling unit were the Arctic Cooling Accelero X2 and the Zalman VF900-CU.

The first device was the stock cooler that comes with the card. The first impressions of this cooling unit is that it may just have the edge over specialised air coolers due partly to its reasonable sized heat sink and an equally reasonable sized fan. So the big question is would the cooling unit prove to be sufficient in keeping this beast of a graphics card cool under a high load? ........................NO!
So what exactly are the reasons for such poor performance? Quite clearly the cooling unit is lacking the capacity to absorb enough heat to allow for effective heat dissipation. The cooling fan does not seem to have the ability to blow enough air through the heat sink which is a major draw back. However the fan is not as bad as the results will have you believe as a high amount of hot air blows out through the grill on the card. Initially when the system powers up the cooling fan starts spinning at a fast rate then slows down to almost being un-noticeable, which may be one of the factors in its high temperatures. However not all can be blamed on the heat sink and fan alone. The thick plastic cover seems to work against the fan and heat sink by helping to retain the heat generated by the card.

The next unit that we tested was the Arctic Cooling Accelero X2. The first impressions had me convinced of its ability. This unit has a very large heat sink, which boasts a copper core for the GPU and uses heat pipe technology to move heat away from the cards components. To blow heat away from the heat sink is a fan which uses a fluid dynamic bearing to allow for higher RPMs while keeping the noise level to a minimum. The Accelero X2 also comes with a nice little feature in that it already has thermal grease pre-applied, which makes things much easier and cuts out the messy task of doing it yourself. 8 Additional heat pads are also supplied with the unit. To attach this cooler to graphics card is a very straight forward process which only takes a couple of minutes to do and looks like so:

As the results show the Accelero X2 is more effective than the stock cooling unit, however the difference is so marginal that it begs the question why? On first impression it would appear that cooler is lacking in something. It would be easy to blame the fan for how quiet it is, but this is deceiving as it draws a nice amount of air into the unit. The Accelero X2 is a good cooler with one simple flaw. The only place for the hot air to escape is downwards straight on to the base of the card. It is highly possible that this is having an adverse effect on the card.

The final cooling unit that we put to the test was the Zalman V900-CU. And just looking at this cooling unit, you somehow know that this is going to be something special. This unit has a nice and smooth copper contact patch for the GPU and uses heat pipes which are surrounded by copper fins for a maximum surface area. In the centre of all this copper is an 80mm 2 bearing fan. The cool thing about this cooler is that it comes with a controller so depending on what you are doing you can adjust it to run at anywhere between 7 and 12 volts. The 7 volt setting is incredibly silent and the 12 volt setting is quite enough to be un-noticeable. The cooler also comes with 8 small heat sinks which are used to provide heat relief to the graphics memory. The installation of this unit is very easy and straight forward. Once installed it looks rather cool as the pictures below shows.

The Zalman cooler is a light weight unit and as a result doesn’t exert much force on the card itself. The results clearly indicate that the Zalman has the edge over the others with both low and high speeds on the fan. This is truly a great cooling unit and if you are of the opinion that a computer not only has to look good but perform equally well then this is a must.

The results gained from our tests are shown below:

So in the end what conclusions can be drawn from this? It would be unfair to write off the other coolers and just go for the Zalman V900-CU. Arctic Cooling’s Accelero X2 is a good cooler and in a nicely ventilated case there is no doubt that it would do the job and do it well. As for the stock cooling unit, it is almost there and with a couple of adjustments it would give the other coolers a run for their money. On the day the Zalman V900-CU proved itself as the most outstanding candidate for the job, however with the competition in the gaming market heating up it can only mean good things are on the way for cooling. The future seems bright and we will be there to see just how the next generation of coolers perform.