Pentium

Intel's superscalar successor to the 486. It has two 32-bit 486-type integer pipelines with dependency checking. It can execute a maximum of two instructions per cycle. It does pipelined floating-point and performs branch prediction. It has 16 kilobytes of on-chip cache, a 64-bit memory interface, 8 32-bit general-purpose registers and 8 80-bit floating-point registers. It is built from 3.1 million transistors on a 262.4 mm^2 die with ~2.3 million transistors in the core logic. Its clock rate is 66MHz, heat dissipation is 16W, integer performance is 64.5 SPECint92, floating-point performance 56.9 SPECfp92.

It is called "Pentium" because it is the fifth in the 80x86 line. It would have been called the 80586 had a US court not ruled that you can't trademark a number.

The successors are the Pentium Pro and Pentium II.

The following Pentium variants all belong to "x86 Family 6", as reported by "Microsoft Windows" when identifying the CPU:

Model Name 1 Pentium Pro 2 ? 3 Pentium II 4 ? 5, 6 Celeron or Pentium II 7 Pentium III 8 Celeron uPGA2 or Mobile Pentium III

A floating-point division bug was discovered in October 1994.

[Internal implementation, "Microprocessor Report" newsletter, 1993-03-29, volume 7, number 4].

[Pentium based computers, PC Magazine, 1994-01-25].

(2003-09-30)