The Pentium 4 bran refers to Intel's line of single-core mainstream desktop and laptop central processing units (CPUs) introduced on November 20, 2000 (August 8, 2008 is the date of last shipments of Pentium 4s). They had the 7th-generation architecture, called NetBurst, which was the company's first all-new design since 1995, when the Intel P6 architecture of the Pentium Pro CPUs had been introduced. NetBurst differed from the preceding Intel P6 - of Pentium III, II, etc. - by featuring a very deep instruction pipeline to achieve very high clock speeds (up to 4 GHz) limited only by max. power consumption (TDP) reaching up to 115 W in 3.6–3.8 GHz Prescotts and Prescotts 2M (a high TDP requires an additional cooling that can be noisy or expensive). In 2004, the initial 32-bit x86 instruction set of the Pentium 4 microprocessors was extended by the 64-bit x86-64 set.