This rare gem is an AMD Phenom II X4 960T Black Edition that has won the silicon lottery! In the mid-to-late 2000's, some AMD processors by chance could be "Core Unlocked", a feature supported by most AMD motherboards from the era. Essentially, AMD would sell processors as quad-core or dual-core, but the actual silicon had a higher core count, with some cores disabled. By turning on "Core Unlocker" in the BIOS, it was sometimes possible to re-enable these extra cores. In the case of this 960T, the silicon it used was actually an early six-core attempt that AMD determined wasn't viable for some reason, and so it was repurposed as the quad-core 960T. If you use CPU-Z, you'll find that the fully-core-unlocked name for this processor is the AMD Phenom II X6 1605T, feel free to google it and find out more! I've fully tested both the 960T and 1605T modes of this chip, and it's fully stable and runs great! AMD stopped the practice of leaving fully functional but disabled cores in their processors after this generation, and it was pretty rare to find one that was unlockable in the first place! I've had this chip in my collection for a couple years, running retro games on it and enjoying the rarity and uniqueness of this processor, and I hope you can enjoy and appreciate it as much as I have! Feel free to message me with questions :)