AC Accelero Xtreme 8800: view inside the box
Mainboards and VGA cards come with a handful of additional tools to increase the product value for the customer, with cooling devices you won't find those nice extras, besides a simple fan controller everything remains as simple as possible. Likewise, inside your Accelero Xtreme product box you'll basically find just the air cooled heatsink with just some basic requirements to properly install the device. Have a look:One Arctic Cooling Accelero Xtreme 8800
Twelve thick thermal pads
One thin thermal pad
Four voltage regulator heatsinks
One Arctic Cooling sticker
One slot bracket
One Installation Guide
First impressions left me with a good feeling, no aggressive looks but considering the size of this heatsink it might be well capable of dealing with the current competition. In real life, this heatsink is a lot bigger then the standard 8800GTS heatsink, but we will come back on this later.
The Accelero Xtreme heatsink consist out of two aluminum heat exchangers brought together via a set of heatpipes. The main heatsink, which is the biggest one, counts 62 of the total 107 cooling fins, with each fin being bigger then 26,5cm² this results in more then 3800cm² of surface area. And that is just the main heatsink, the second heatsink counts 35 fins of each 17,5cm² big, that is a nice addition of another 123cm² cooling surface which brings the total to over 500 square centimeter, even a lot of today's CPU heatsink come nowhere near that number!
The smaller heatsink does not only count a lesser amount of cooling fins, the height has also been adjusted to make sure that the heatsink does not get in way of any of the video card 12V capacitors.
On top of the heatsink AC has build a fan holder which should be well capable of eliminating the humming noise produced by the electrical fans. Although this mounting method is patented, I don't really see why it would make that much of a difference if the fans were mounted differently.
The Accelero Xtreem heatsink is made to be cooled by three 80mm fans, placed over the entire cooling area those do not only feed the heatsink with lot's of cool air, they also give the VGA PWM area a nice cold breeze, you will have a hard time overheating any of your Geforce 8800 board components this way. The fans no longer use the ball type bearing, instead they moved on to fluid dynamic bearing (FDB):
image courtesy of Hitachi.com
With fans, the source of sound is found in the moving fan blades and the brushless fan motor components. Bearing is one of the motor components, the advantage of using FDB is that you no longer need the mechanical balls used with traditional types of bearings, this makes fluid dynamic bearing better in all sorts of things: higher damping, reduced frequency resonance, better non-operational shock resistance, greater speed control, improved acoustics, and few other benefits which do not really relate to the functioning of DC fans. Noise wise, FDB should be around 4dBA less than traditional bearing types while their longevity has been doubled/tripled!
We found the fans to be PWM compatible, a 4 pin header can be plugged into your Geforce 8800 G80 video card and via the Rivatuner (or other) software we could easily adjust the fan duty cycle up to 2000 rpm (100% duty cycle).
The base of the heatsink is a large aluminum plate with a center copper core. The base plate is made this large because it combines the GPU and memory cooling, via thermal pads AC found and easy way to keep the base design as simple as possible while the installation procedure does not get longer in time or more complicated then compared to other heatsinks.
The heatpipe structure is all focused on the GPU, the 5 heatpipes found within this heatsink all gather inside the copper center in order to spread the GPU thermal energy as good as possible. The Accelero Xtreme comes with pre-applied high performance thermal compound and should make the first installation nearly hassle free. I've been told that the compound is nothing else then AC's well performing MX-2, another advantage which adds up to the value of this heatsink.
Like said above, the heatpipes all gather inside the copper center core of the heatsink. From there on you'll find three pipes traveling to the second smaller heatsink, while the remaining 2 heatpipes are bound directly back inside the main heatsink to make sure that GPU heat is spread evenly over the entire cooling surface. Also notice how the heatsink got small mini-fins inside, AC used solder to attach those mini-fins to the heatpipes, this will certainly improve the heat transferring efficiency of this heatsink. From our above mentioned specifications you may have noticed the thermal resistance of the Accelero Xtreme heatsink. The thermal resistance of a cooling device is a great way to express the actual performance of the unit, as far as I can see 0,14°C/Watt really is nearly the best you can get these days with air cooled heatsinks, the Tuniq Tower 120 CPU cooler needs a bloody fast 120mm fan to come even close to the AC Accelero Xtreme!
You already might want to jump straight ahead to the performance chart, but please, let me first give you some information about the installation procedure, and how easy it was to get this heatsink mounted ->