Since the nForce4's release, the chipset's ActiveArmor networking capabilities have struggled to live up to their promised potential for reducing CPU utilization by handling TCP checksumming in hardware rather than on the host CPU. Over time, we've watched ActiveArmor's CPU utilization oscillate between impressively low and alarmingly high. Every new driver release seemed to change ActiveArmor's CPU utilization, and to make matters worse, many found that using ActiveArmor at all could lead to data corruption or instability.

The TechReport