Intel's Pentium 4 fiasco is already a distant memory for most computer enthusiast but the Pentium 4 is back in the news today as the chip giant has settled a long-running legal battle which accused Intel of rigging benchmarks to make its Pentium 4 chip come out more favorably.
What it comes down to is that you might be eligible for a $15 cash rebate if you bought a computer with a Pentium 4 processor between November 20, 2000 and June 30, 2002. You can find the full details at this website but unfortunately it's only for United States residents (other than those residing in Illinois).
The goal behind NetBurst was to create an architecture that would scale to clock frequencies as high as 10GHz, speeds at which the raw throughput of the chips would more than compensate for its decreased IPC. Sadly, things didn't work out that way: rather than 10GHz, Intel barely made it to 3.8GHz before the power required and the heat generated by the chips became unmanageable. For its next-generation Pentium M mobile processors, the company would abandon NetBurst and return to the P6 microarchitecture before ditching NetBurst altogether and creating a more P6-inspired microarchitecture, still in use today, dubbed Core.
In short: the Pentium 4 was a colossal and costly mistake for Intel. A class action suit brought against Intel and HP claimed that the companies knew from the outset that the Pentium 4 was too slow and ran too hot, and that the companies collaborated on customised benchmarks - WebMark 2001 and SYSmark 2001 - which would concentrate on the things the chip was good at to paint a far rosier picture of its performance compared to the previous generation Pentium III processors which it replaced.