Three Cores instead of four. AMD follows in the footsteps of ATI's "Pro" series to increase yield on the Phenom series. As it turns out, though, it is not just an issue of reducing the number of cores and incur some scaling back of performance, there are also software recognition and licensing issues that come into play. In the end, while the Phenom X3 performs admirably well in some applications, it's performance comes in last in a number of other applications simply because, in a triple core configuration, those will only utilize a single core.