Pentium III:

The Pentium III brand refers to Intel's 32-bit x86 desktop and mobile microprocessors (with the sixth-generation Intel P6 microarchitecture) introduced on February 26, 1999. The initial Katmai Pentium III contained 9.5 million transistors. The brand's initial processors were very similar to the earlier CPUs branded Pentium II. The most notable difference was the addition of the SSE instruction set (to accelerate media processing and 3D graphics), and the introduction of a controversial serial number embedded in the chip during the manufacturing process.

Similarly to the Pentium II it superseded, the Pentium III was also accompanied by the Celeron brand for lower-end CPU versions, and the Xeon for high-end (server and workstation) derivatives. The Pentium III was eventually superseded by the Pentium 4, but its Tualatin core also served as the basis for the Pentium M CPUs, which used many ideas from the Intel P6 microarchitecture. Subsequently, it was the P-M microarchitecture of Pentium M branded CPUs, and not the NetBurst found in Pentium 4 processors, that formed the basis for Intel's energy-efficient Intel Core microarchitecture of CPUs branded Core 2, Pentium Dual-Core, Celeron (Core), and Xeon.

The Pentium III was the first Intel processor to break 1 GFLOPS, with a theoretical performance of 2 GFLOPS.