Board analysis

Enhanced cooling

Without a doubt, the heart of EVGA’s e-GeForce 7800 GTX KO ACS³ is its unique ACS³ cooling unit, so we’ll start there first. While EVGA’s ACS³ cooler looks like one component at first glance, it’s actually composed of multiple layers.

The many layers of the EVGA KO board

The heart of EVGA’s ACS³ cooler is arguably its copper heatsink unit. The basic design of EVGA’s copper heatsink looks like its borrowed largely from NVIDIA’s reference cooling unit used on most 7800 GTX cards, with the exception of course that EVGA uses a copper heatsink to help keep the GPU cool while NVIDIA’s reference design relies on aluminum. If you happened to check out our GeForce 7800 GTX Performance Preview back in June, you probably noticed the first picture, which depicted an early pre-production GeForce 7800 GTX card with copper cooling:

Original GeForce 7800 GTX reference card with copper cooling

Once you exclude the copper heatpipe used to cool the GeForce 7800 GTX card pictured above, EVGA’s ACS³ cooler appears to be largely the same as NVIDIA’s original cooling design. We have a feeling that NVIDIA likely chose to go with an aluminum heatsink for their 7800 GTX reference design rather than copper to keep production costs down. NVIDIA’s board partners (including EVGA) likely stuck with this reference aluminum cooler for the same reason. Our guess is that since the e-GeForce 7800 GTX KO ACS³ is targeted for enthusiasts, EVGA knew NVIDIA’s stock aluminum cooler wouldn’t suffice for their needs and decided to go with the more robust cooling unit.

Top of the EVGA card

Bottom of the card

Sitting directly over the G70 GPU, underneath EVGA’s aforementioned copper heatsink, is a large aluminum metal plate with aluminum fins on the edges, as well as an aluminum heatpipe. These appear to be the exact same components used on every GeForce 7800 GTX card we’ve seen to date. If you click back to our shots of the pre-production 7800 GTX reference board, you’ll notice that it too has the aluminum plate and fins. Knowing how thorough NVIDIA’s engineers are, our guess here is that NVIDIA determined that aluminum is the metal of choice for this particular cooling application rather than copper; EVGA must have then run their own analysis for their ACS³ cooler and came to the same conclusion, using aluminum for the fins and plate rather than copper.

Air runs through this duct, which also acts as an additional heatsink

On top of these two layers lies the most visible aspect of the e-GeForce 7800 GTX KO ACS³ card, its black casing. The black casing is composed of aluminum and actually acts as a ducting unit, channeling air from the card’s fan all the way across the back of the board, where hot air exits from. NVIDIA’s duct used on the 7800 GTX is much shorter, stopping just behind the board’s memory modules, and since EVGA uses aluminum (rather than the plastic used by NVIDIA) the duct doubles as an additional heatsink, drawing heat off the graphics card.

Air passes through here too

For added flair, EVGA then adorns their aluminum duct with dozens of tiny “E”s, the company’s new logo. These logos not only serve as a decoration, they also provide additional ventilation for the card’s ducting system.

As a result of the changes EVGA has implemented to their ducting system, their ACS³ cooler is capable of pushing more air through its cooler because its duct is longer, with the added benefit of having more ventilation -- think of it like a river with multiple channels.