AMD has been shipping some three and dual core CPUS with some of the cores disabled. Asus has devised a Core Unlocker switch and placed it on its board. When enabled, the switch attempts to open up those disabled cores.
It sounds too good to be true and for the most part it is. Asus doesn't guarantee that the Core Unlocker will succeed with every processor.
AMD disables that core because it can't be sure if it will work reliably, or particularly well. Although it will not say if using the feature will void the chip's warranty. It refused to support the motherboard's feature which is a bit of an ominous sign.
However those who build and overclock their own systems laugh in the face of voiding warranties already. The M4A89GTD Pro includes Asus' TurboV EVO processor to help you find the highest clock speed to overclock to while keeping your system stable.
The M4A89GTD PRO is based on the latest AMD 890GX chipset, launched . It supports both the integrated graphics core as well as discrete GPUs. A "GPU Boost" utility will overclock the integrated graphics core via voltage and frequency adjustments.
The motherboard adds a pair of external USB 3.0 ports (if the "/USB3" derivative is bought), one of the first to do so. Asus also claimed that the board is the first to use a SATA 6 Gbit/s interface. It seems to be around for about $145 which could see it under the bonnet of machines in a four core for the price of three.