CPU locking
From Wikipedia, the free encyclopedia
CPU locking is the process of permanently setting a CPU's clock multiplier. AMD CPUs are unlocked in early editions of a model and locked in later editions, but nearly all Intel CPUs are locked and recent models are very resistant to unlocking to prevent fraudulent CPU speed claims by resellers. Intel's Core 2 Extreme X6800 (dual core) and QX6700 (quad core) CPUs, staples of the Extreme Edition lineup, ship with unlocked multipliers, as do AMD's FX series.
Users unlock CPUs to allow underclocking, overclocking, and front side bus speed compatibility with certain motherboards, but unlocking invalidates the manufacturer's warranty and mistakes can cripple a CPU. However, locking a chip's clock multiplier does not necessarily prevent users from over-clocking, as the speed of the front-side bus can still be tweaked to provide a performance increase. AMD CPUs are generally unlocked by connecting bridges (jumper-like points) on the top of the CPU with conductive paint or pencil lead. Other CPU models (determinable by serial number) require different procedures to be unlocked.
One of the easiest ways to unlock a CPU is the pin mod method, because it's possible to unlock the CPU without a permanent modification of any bridges. Just one fine wire (or some more for a new multiplier/Vcore) into the socket will unlock the CPU.
