2000-11-20 Intel Pentium 4 P6, formerly known as Willamette, enhanced for speed in a number of ways, for example added decoders, execution units, larger buffers, a longer pipeline, an "instruction trace cache", and 256KB of on die L2 cache. The core runs at twice the clock speed and uses two ALUs. Uses a 400 MHz front side bus. Starts at 0.18 um shrinking to 0.13 later while clock speed moves from 1.5 GHz and up. Pricing 1.4 GHz: $625, 1.5 GHz: $795. Speeds up to 1.7 GHz in Q1 2001, and at or above 2 GHz in Q3.
2002-01-07 Intel Pentium 4 2.2 Willamette core shrunk to 0.13 um starting at 2.2 GHz introduced at $562. Uses the 478 pin socket and the Tehama or Brookdale North Bridge. Includes 512 kB cache.