Difference between Pentium 3 and Pentium 4 Processors:

The difference between Pentium 3 and Pentium 4 Processors is given in table below

Pentium III Processor

Pentium IV Processor

Pentium III processor is a sixth-generation processor and it is represented by the P6 family processor. This processor was developed in 1999 by Intel. Pentium 4 processor is the seventh generation processor. This processor was developed in 2000 by Intel.
Pentium III processor was manufactured based on the P6 micro-architecture. Pentium 4 was manufactured base on NetBurst micro-architecture.
This processor core contains 9.5 to 28 million transistors. This processor core contains 42 million transistors.
Pentium III operates at 2.0 V to 1.45 V. Pentium 4 operates at 1.40 V to 1.25 V.
This processor is available at operating frequencies of 450 MHz to 1.4 GHz. Clock speed of Pentium 4 varies from 1.3 GHz to 3.8 GHz.
It supports faster system bus at 100 MHz to 133 MHz. It supports faster system bus at 400 MHz to 1066 MHz with 3.2 GB/s of bandwidth.
Pentium III Katmai was fabricated in a 0.25 μM CMOS process. It is fabricated in 0.18 micron CMOS process.
Pentium III has 32 Kbyte L1 cache-16 Kb for instruction and 16 Kb for data. Pentium 4 has 12 Kb L1 cache for code and 8 Kb for data.
It has on-die 0 to 512 Kb L2 cache It has on-die 512 Kb L2 cache.
This processor has SSE (streaming SIMD) t extensions. It can support dynamic execution technology. 70 new instructions are added to the Pentium III for multimedia and advanced image processing applications. The instruction set of Pentium 4 processor is compatible with x86 (i386), x86-64, MMX, SSE, SSE2, and SSE3 instructions. These instructions include 128-bit SIMD integer arithmetic and 128-bit SIMD double-precision floating-point operations.