Page 10 - Noise Factor and Conclusion

In our temperature tests, we've simulated the mark in a standard working environment to reflect upon real life temperatures. This is based on the direct heat exhaust capabilities of the heatsink, as well as the cooling ability of the stock cooler.
The ATI Radeon HD 3870, even when factory overclocked by Asus, doesn't run too hot -- partially due to the low power consumption by its 55nm core. The implementation of ATI PowerPlay to slow down the card when idling is definitely a benefit -- in this state, the dual slot cooler has the GPU around 52c and is almost inaudible. Under load, the temperature shoots up to 77c with variable fan control. The fan on the Radeon HD 3870 would spin up and slow down periodically to push the heat out. I actually found this to be very annoying during usage when the fan spins up and slows down a few times per minute.
Again, under idle conditions, the low RPM fan on the stock cooler is actually very quiet. In fact, it is almost not audible in relation even to our extremely quiet configuration of Noctua NF-S12-800 in front, Noctua NF-S12-1200 at the back with Asus Q-Fan enabled to drop it to around 800rpm, Noctua NF-P12 on our NH-U12P heatsink, powered by a Seasonic M12 power supply with a low RPM ADDA fan.
From an acoustic and subjective scale from 0-10 where 0 is silent and 10 being the loudest, I would rate the Asus EAH3870 TOP's cooler to be at 3.0/10 under idle conditions. As the fan spins up under load, it gets quite loud -- which is then clearly audible. Under maximum load, I would rate the stock cooler to be at 6.0/10 on our proprietary acoustical noise scale. But how it spins up and down a few times a minute when it's under load is still really annoying.
Special thanks to Wil over at Asus for making this review possible.

APH equal.balance Award
Starting from April 30, 2007, Number Ratings has been dropped for motherboards, RAM, and graphics cards. This is to ensure the most appropriate ratings reflected without the limits of using numbers. Everything else will continue using the Number Rating System.
More information in our Review Focus.
The ATI Radeon HD 3870 strikes a sweet spot between price, performance, and efficiency. Asus enhanced it with the EAH3870 TOP and made it better with excellent memory overclocking headroom.