Arctic Cooling's last cooler compatible with the X1900XTX was the Accelero X2. This cooler, said to be effectively silent at full fan speed, achieved great temperatures. However, some users complained about some unacceptable design flaws, including that the RAM-sinks were practically glued on upon first installation. This meant that if you didn't like your Accelero X2, or if you wanted to try something new, you were stuck. In this vein, the Accelero S1 has very specific instructions involving fan orientation and case setup for optimal performance. They describe how all fans should be directed outwards, and any grills in the case exterior for increased airflow should be somehow blocked off. In this review, I'll compare both their suggestion and my original case setup to see what's really happening.