Our thanks go to a large PC vendor, who was able to give us a hand-picked processor that is particularly suited to air-cooled overclocking. The fact is, the majority of existing, available Pentium 4/2200 CPUs with the Northwood core do not run stably at the extreme clock speeds higher than 3000 MHz, no matter what tricks you use. In any case, going over 3GHz cannot be achieved with traditional CPU coolers based on a heatsink and fan. However, the picture changes completely when you use a high-performance water cooling system, or even a hermetic sub-zero cooling system with an evaporator. Only then can the temperature of the CPU die be kept under 20 degrees Celsius.