RapidCAD is a specially packaged Intel 486DX and a dummy
floating point unit
Floating may refer to:
* a type of dental work performed on horse teeth
* use of an isolation tank
* the guitar-playing technique where chords are sustained rather than scratched
* ''Floating'' (play), by Hugh Hughes
* Floating (psychological ...
(FPU) designed as pin-compatible replacements for an
Intel 80386
The Intel 386, originally released as 80386 and later renamed i386, is a 32-bit microprocessor introduced in 1985. The first versions had 275,000 transistors80387 FPU. Because the i486DX has a working on-chip FPU, a dummy FPU package is supplied to go in the Intel 387 FPU socket. The dummy FPU is used to provide the FERR signal, necessary for compatibility purposes.
Despite being able to execute instructions in the same number of cycles as an i486DX, integer performance on RapidCAD suffers due to the absence of level 1 cache and the bottleneck of the 386 bus. RapidCAD offers minimal improvement in integer performance over a 386DX (typically 10%, at most 35%), but provides substantial improvement in floating point operations (up to 80% faster) for which it was marketed. Floating point performance is mostly improved by moving the FPU onto the CPU core.
File:KL intel RapidCAD1.jpg, Intel RapidCAD-1
File:KL intel RapidCAD2.jpg, Intel RapidCAD-2
Pentium OverDrive The Pentium OverDrive was a microprocessor marketing brand name used by Intel, to cover a variety of consumer upgrade products sold in the mid-1990s. It was originally released for 486 motherboards, and later some Pentium sockets. Intel dropped the ...