Pentium 3 processors come in two packaging formats. While Intel is moving toward the Flip Chip Pin Grid Array - FCPGA, they do offer Coppermine processors based on the legacy Single Edge Contact Cartridge - SECC 2 - Slot 1 architecture. The Abit BH6 motherboard accepts a Slot 1 processor.
Pentium 3 processors currently range from 450MHz up to 1GHz as illustrated in the following table. Note that processors marked with a "B" suffix support a 133MHz system bus frequency, while a suffix of "E" represents processors with advanced transfer cache:
Pentium 3 Processors - 450MHz to 1.0GHz

The Coppermine is the first processor made by Intel that uses a .18 micron core meaning that the transistors are .18 microns apart. The smaller distance between the transistors allows the Coppermine to be made cheaper, run faster, cooler, and draw less voltage compared to its predecessor - the Katmai. Compared to the .25 micron based Pentium 2/3 Katmai, which requires 2.0 volts of electricity, most Coppermines operate at 1.65 volts.
Pentium 3 Processors - Voltage Specifications

A significant difference in Coppermine processors is the addition of Advanced Transfer Cache which means that the processors 256KB of on-die L2 cache runs at the same speed as the processor. This is in comparison to the Katmai's 512KB of L2 cache which runs at half the processors clock speed. The Coppermines L2 cache is connected to the processor core via a 256-bit wide data path which is four times as wide as the Katmai's 64-bit wide data path. This significantly increases the data bandwith between the processor and L2 cache. Both types of processors continue to use a 32KB L1 cache.
Intel Pentium 3 Processors - L2 Cache Types

Finally, the Pentium 3 offers Streaming SIMD Extensions (SSE) which are 71 new instructions that increase the efficiency of floating point operations. NVIDIA's Detonator drivers include support for SSE which can provide a 5-10% increase in performance over the Pentium 2 or Celeron in games such as Quake 3.
Note: The images used on this page were obtained from documentation provided at Intel's web site and are used for illustration only.
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