The new CAM apparently uses spintronics features, which take advantage of the negative charge of electrons as well as magnetic spin characteristics. Using the vertical magnetization of vertical domain wall elements in reaction to magnetic substances, NEC says that technology is able to store data without consuming power.
CAM is generally much faster than standard RAM, since it searches its entire content within one operation. However, CAM is much more expensive to manufacture as it has larger, more complex storage cells that include comparison circuits, and CAM is traditionally also more power hungry as well. The fact that NEC now has CAM that can operate while cutting off its power source appears to be an astonishing achievement.
The company also claims that it has substantially reduced the size of the CAM: The new memory is about 50% smaller than previous CAMs. NEC is showcasing its invention at the VLSI Circuit Symposium, which is currently held in Kyoto, Japan. There was no information when the power-less CAMs will be commercially available.