The SX had a 16-bit external data bus, and that made it possible to build cheap PC's.
X 86 instructions was utmost implemented by 80486, due to which it executed faster, in a more RISC (Reduced Instruction Set Computing)1 like manner. The 486 was also the first CPU with built-in L1 cache. The 486 working was twice as efficient and fast as 386 and with the same clock frequency.
486 was a multi user and multitasking operating system, which worked under several other operating systems like DOS, Windows 3.11 and Windows 95. New editions were released with higher clock frequencies and double-clocked processors named 80486 DX2. (Michael Karbo)
Intel Corporation's microprocessor released in 1993, was the first fifth generation CPU incorporating more than 3.1 million transistors, the 32-bit Pentium processor is a highly integrated semiconductor device that has an external bus width of 64 bits. The first release featured clock speeds of 60 and 66 megahertz (MHz) achieving a performance of over 100 Mips2. It is almost twice as fast as the Intel 486 DX2 Microprocessor.
This performance is largely due to the Pentium Processors superscalar3 Architecture. Its dual execution pipeline implementation utilizes advanced design techniques that enable it to transparently execute multiple instructions per clock cycle. The Pentium Processors enhanced 64-bit data bus carries information between the processor and the memory subsystems at 528 MB per second at 66 MHz. Other features of the Pentium Processor include:
Floating point unit
64 bit data bus
Memory page size option
Error detection and functional redundancy
Overdrive processor upgradability and
(Jonar C. Nader, 3rd edition)
Pentium II Processor
Released in 1997, this microprocessor incorporated 7.5 million transistors. This 64-bit processor was first released in clock speeds of 266 MHz and 300 MHz and 64 gigabytes of addressable memory and 64 terabytes of virtual memory.
In order to make the production cheaper Intel chose to place the cache outside the actual Pentium II chip. The disadvantage of this system was that the L2 cache became markedly slower than it