WinChip

WinChip

IDT WinChip
Produced	From 1997 to 1999
Common manufacturer(s)	Centaur / IDT
Max. CPU clock	180 MHz to 250 MHz
FSB speeds	60  to 100
Min. feature size	0.35 to 0.25
Instruction set	x86
Socket(s)	Socket 7
Core name(s)	C6 W2, C6+ W2A W2B W3

The WinChip series was a low-power Socket 7-based x86 processor designed by Centaur Technology and marketed by its parent company IDT.

Overview

The design of the WinChip was quite different from other processors of the time. Instead of a large gate count and die area, IDT, using experience from the RISC processor market, created a small and electrically efficient processor similar to the 80486, because of its single pipeline and in-order execution architecture. It was of much simpler design than that of its competition, such as AMD K5/K6 and Intel Pentium II, which were superscalar and based on dynamic translation to buffered micro-operations with advanced instruction reordering (out of order execution).

WinChip was, in general, designed to perform well with popular applications that didn't do much (if any) floating point calculations. This included operating systems of the time and the majority of software used in businesses. It was also designed to be a drop-in replacement for the more complex, and thus more expensive, processors it was competing with. This allowed IDT/Centaur to take advantage of an established system platform (Intel's Socket 7).

WinChip 2A added fractional multipliers and adopted a 100 MHz front side bus to improve memory access and L2 cache performance.^[1] It also adopted the performance rating concept, similar to how AMD and Cyrix marketed their processors. This method of specifying processor performance helped consumers understand where the WinChip's performance fit in against Intel's competing products. Another revision (2B) was also planned, with a die shrink to 0.25 μm, but was shipped in limited numbers.^[2] A third WinChip was planned as well, this one receiving a doubled L1 cache, but that CPU never made it to market.^[2]

The industry's move away from Socket 7 and the release of the Intel Celeron processor signalled the end of the WinChip. In 1999, the Centaur Technology division of IDT was sold to VIA. Although VIA initially branded processors as "Cyrix," the company initially used technology similar to WinChip with its Cyrix III line.^[3]

Performance

Although the small die size and low power-usage made the processor notably inexpensive to manufacture, it never gained much market share. WinChip C6 was a competitor to the Intel Pentium and Pentium MMX, Cyrix 6x86, and AMD K5/K6. It performed adequately, but only in applications that used little floating point math. Its floating point performance was well below that of the Pentium, being similar to the Cyrix 6x86.^[4] The WinChip 2 added a 3DNow! processing unit to strengthen floating point performance. Unfortunately its 3DNow! unit was not as fast as that in AMD K6-2.^[5] This successor targeted the Intel Pentium II, Cyrix MII, and AMD K6-2 processors as competitors.

WinChip Data

Processor	Speed (MHz)	FSB (MHz)	L1 cache (KiB)	L2 cache (KiB)	SIMD	Pipeline Stages	Max TDP	Core (V)	Process (nm)
WinChip C6[6]	180 - 240	60 - 75	64	0	MMX	4	13.1 W at 240 MHz	3.52	350
WinChip 2[2]	200, 225, 240	60 - 75	64	0	3DNow!, MMX	4	14.0 W at 240 MHz	3.52	350
WinChip 2A[2]	200, 233, 250 PR200, PR233, PR300	66 / 100	64	0	3DNow!, MMX	4	16.0 W at 250 MHz	3.3, 3.52	350
WinChip 2B[2]	200, 200 PR200, PR233	66 / 100	64	0	3DNow!, MMX	4	6.3 W at 200 MHz	2.80	250
WinChip 3[2]	unreleased	66 / 100	128	0	3DNow!, MMX	4		2.80	250

See also

• List of VIA microprocessors

References

1. ^ Hare, Chris. Processor Speed Settings, accessed April 24, 2007.
2. ^ ^{a b c d e f} IA-32 implementation: Centaur WinChip 2, SandPile.org, accessed April 29, 2007.
3. ^ Witheiler, Matthew. The New VIA Cyrix III: The Worlds First 0.15 Micron x86 CPU, AnandTech, January 5, 2001.
4. ^ Pabst, Thomas. The IDT WinChip C6 CPU, Tom's Hardware, October 9, 1997.
5. ^ IDT Winchip 2 266 Review, X-bit labs, April 18, 1999.
6. ^ IA-32 implementation: Centaur WinChip, Sandpile, accessed May 13, 2007.

External links

• Centaur Technology
• CPU-INFO: IDT C6, in-depth processor history
• VIA CPU Overview at CPUShack
• WinChip architecture at Sandpile.org
• WinChip2 architecture at Sandpile.org
• CPUPages W2B
• Winchip W2, W2A, W2B UKcpu
• Winchip2B