
Serbian overclocker d0minat0r unlocked the third core on an AMD Phenom II X2 570 BE and pushed it to 6473 MHz using liquid nitrogen.
AMD's Phenom II dual-, triple-, and quad-core chips are famous for how easily you can unlock their hidden cores. For the Phenom II X2, you can unlock a third or even a fourth core. The Phenom II X3 can become a quad-core. Even with certain quad-core Phenom II X4 chips (specifically 'T' models like the Phenom II X4 960T), you have a rare but very real chance to get a six-core CPU completely free.
Serbian overclocker d0minat0r successfully took advantage of this trick, unlocking a third core on his dual-core AMD Phenom II X2 570 BE. Using liquid nitrogen, he pushed this newly minted 'triple-core' chip to a blistering 6473 MHz. This feat secured him first place in the HWBOT x265 Benchmark - 4k category, both for this specific CPU model and in the global triple-core rankings:
The core voltage was pushed to 1.904V, while the DDR3 memory clocked in at 1327 MHz with tight 6-6-6-18-33 1T timings.
The test bench included the following hardware:
Motherboard: GIGABYTE GA-MA770T-UD3P;
Graphics card: NVIDIA GeForce GT 610;
OS: Windows 7.
Source: HWBot submission page