WinChip

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

WinChip

IDT WinChip Marketing sample
General Info
Launched	1997
Discontinued	1999
Marketed by	IDT
Designed by	Centaur Technology
CPUID code	0540h, 0541h, 0585h, 0587h, 058Ah, 0595h
Performance
Max. CPU clock rate	180 Mhz to 266 Mhz
FSB speeds	60 MT/s to 100 MT/s
Cache
L1 cache	64 KiB (C6, W2, W2A and W2B) 128 KiB (W3)
L2 cache	Motherboard dependent
L3 cache	none
Architecture and classification
Min. feature size	0.35 µm to 0.25 µm
Microarchitecture	Single, 4-stage, pipeline in-order execution
Instruction set	x86 (IA-32)
Physical specifications
Cores	1
Package(s)	CGPA (C6, W2, W2A, W3) PPGA (W2B)
Socket(s)	Socket 5 Socket 7 Super Socket 7
Products, models, variants
Core name(s)	C6 W2, C6+ W2A W2B W3
Brand name(s)	WinChip
History
Successor	Cyrix III

Overview

Design

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 its 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 microarchitecture. It was of much simpler design than its Socket 7 competitors, such as AMD K5/K6 and Intel Pentium, which were superscalar and based on dynamic translation to buffered micro-operations with advanced instruction reordering (out of order execution).

Use

WinChip was, in general, designed to perform well with popular applications that didn't do many (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).

Later developments

WinChip 2, an update of C6, retained the simple in-order execution pipeline of its predecessor, but added dual MMX/3DNow! processing units that could operate in superscalar execution.[1] This made it the only non-AMD CPU on Socket 7 to support 3DNow! instructions. WinChip 2A added fractional multipliers and adopted a 100 MHz front side bus to improve memory access and L2 cache performance.[2] It also adopted a performance rating nomenclature instead of reporting the real clock speed, similar to contemporary AMD and Cyrix processors.

Another revision, the WinChip 2B, was also planned. This featured a die shrink to 0.25 μm, but was only shipped in limited numbers.[3]

A third model, the WinChip 3, was planned as well. This was meant to receive a doubled L1 cache, but the W3 CPU never made it to market.[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 simply well below that of the Pentium and K6, being even slower than the Cyrix 6x86.[4]

Decline

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 branded the processors as "Cyrix," the company initially used technology similar to the WinChip in its Cyrix III line.[5]

WinChip Data

Winchip C6 (0.35 µm)

• All models supported MMX[6]
• The 88 mm² die was made using a 0.35 micron 4-layer metal CMOS technology.[6]
• The 64 Kib L1 Cache of the WinChip C6 used a 32 KB 2-way set associative code cache and a 32 KB 2-way set associative data cache.[6]
• The size of the unified L2 cache was dependent on the cache available on the used motherboard.

Processor Model	Frequency	FSB	Mult.	L1 cache	TDP	CPU core voltage	Socket	Release date	Part number(s)	Introduction price
WinChip 180	180 MHz	60 MT/s	3	64 KiB	9.4 W	3.45—3.6 V	Socket 5 Socket 7 Super Socket 7 CGPA 296	13 October 1997	DS180GAEM	$90
WinChip 200	200 MHz	66 Mt/s	3	64 KiB	10.4 W	3.45—3.6 V	Socket 5 Socket 7 Super Socket 7 CGPA 296	13 October 1997	DS200GAEM	$135
WinChip 225	225 MHz	75 MT/s	3	64 KiB	12.3 W	3.45—3.6 V	Socket 7 Super Socket 7 CGPA 296	13 October 1997	PSME225GA
WinChip 240	240 MHz	60 MT/s	4	64 KiB	13.1 W	3.45—3.6 V	Socket 5 Socket 7 Super Socket 7 CGPA 296	November 1997?	PSME240GA

WinChip 2 (0.35 µm)

• All models supported MMX[3] and 3DNow![3]
• The 95 mm² die was made using a 0.35 micron 5-layer metal CMOS technology.[3]
• The 64 Kib L1 Cache of the WinChip 2 used a 32 KB 2-way set associative code cache and a 32 KB 4-way set associative data cache.
• The size of the unified L2 cache was dependent on the cache available on the used motherboard.

Processor Model	Frequency	FSB	Mult.	L1 cache	TDP	CPU core voltage	Socket	Release date	Part number(s)	Introduction price
WinChip 2-200	200 MHz	66 MT/s	3	64 KiB	8.8 W	3.45—3.6 V	Socket 5 Socket 7 Super Socket 7 CGPA 296		3DEE200GSA 3DFF200GSA
WinChip 2-225	225 MHz	75 MT/s	3	64 KiB	10.0 W	3.45—3.6 V	Socket 7 Super Socket 7 CGPA 296		3DEE225GSA
WinChip 2-240	240 MHz	60 MT/s	4	64 KiB	10.5 W	3.45—3.6 V	Socket 5 Socket 7 Super Socket 7 CPGA 296		3DEE240GSA
WinChip 2-250	233 MHz	83 MT/s	3	64 KiB	10.9 W	3.45—3.6 V	Super Socket 7 CGPA 296	?

WinChip 2A (0.35 µm)

• All models supported MMX[1] and 3DNow![1]
• The 95 mm² die was made using a 0.35 micron 5-layer metal CMOS technology.[3]
• The 64 Kib L1 Cache of the WinChip 2A used a 32 KB 2-way set associative code cache and a 32 KB 4-way set associative data cache and 3DNow![1]
• The size of the unified L2 cache was dependent on the cache available on the used motherboard.

Processor Model	Frequency	FSB	Mult.	L1 cache	TDP	CPU core voltage	Socket	Release date	Part number(s)	Introduction price
WinChip 2A-200	200 MHz	66 MT/s	3	64 KiB	12.0 W	3.45—3.6 V	Socket 5 Socket 7 Super Socket 7 CGPA 296	March 1999?	3DEE200GTA
WinChip 2A-233	233 MHz	66 MT/s	3.5	64 KiB	13.0 W	3.45—3.6 V	Socket 5 Socket 7 Super Socket 7 CGPA 296	March 1999?	3DEE233GTA
WinChip 2A-266	233 MHz	100 MT/s	2.33	64 KiB	14.0 W	3.45—3.6 V	Super Socket 7 CGPA 296	March 1999?	3DEE266GSA
WinChip 2A-300	250 MHz	100 MT/s	2.5	64 KiB	16.0 W	3.45—3.6 V	Super Socket 7 CGPA 296		3DEE300GSA

WinChip 2B (0.25 µm)

• All models supported MMX[7] and 3DNow![7]
• The 58 mm² die was made using a 0.25 micron 5-layer metal CMOS technology.[3]
• The 64 Kib L1 Cache of the WinChip 2B used a 32 KB 2-way set associative code cache and a 32 KB 4-way set associative data cache.[7]
• The size of the unified L2 cache was dependent on the cache available on the used motherboard.
• Dual-voltage CPU: while the processor core operates at 2.8 Volt, the external Input/Output (I/O) voltages remain 3.3 volts for backwards compatibility.

Processor Model	Frequency	FSB	Mult.	L1 cache	TDP	CPU core voltage	Socket	Release date	Part number(s)	Introduction price
WinChip 2B-200	200 MHz	66 MT/s	3	64 KiB	6.3 W	2.7—2.9 V	Socket 7 Super Socket 7 PPGA 296		3DFK200BTA
WinChip 2B-233	200 MHz	100 MT/s	2	64 KiB	6.3 W	2.7—2.9 V	Super Socket 7 PPGA 296

WinChip 3 (0.25 µm)

• All models supported MMX[8] and 3DNow![8]
• The 75 mm² die was made using a 0.25 micron 5-layer metal CMOS technology.[3]
• The 128 Kib L1 Cache of the WinChip 3 used a 64 KB 2-way set associative code cache and a 64 KB 4-way set associative data cache.[8]
• The size of the unified L2 cache was dependent on the cache available on the used motherboard.

• Dual-voltage CPU: while the processor core operates at 2.8 Volt, the external Input/Output (I/O) voltages remain 3.3 volts for backwards compatibility.

Processor Model	Frequency	FSB	Mult.	L1 cache	TDP	CPU core voltage	Socket	Release date	Part number(s)	Introduction price
WinChip 3-233	200 MHz	66 MT/s	3	128 KiB	? W	2.7—2.9 V	Socket 7 Super Socket 7 CGPA 296
WinChip 3-266	233 MHz	66 MT/s	3.5	128 KiB	8.4 W	2.7—2.9 V	Socket 7 Super Socket 7 CPGA 296	Samples only	FK233GDA
WinChip 3-300	233 MHz	100 MT/s	2.33	128 KiB	8.4 W	2.7—2.9 V	Super Socket 7 CPGA 296	Samples only	FK300GDA
WinChip 3-300	266 MHz	66 MT/s	4	128 KiB	9.3 W	2.7—2.9 V	Socket 7 Super Socket 7 CPGA 296
WinChip 3-333	250 MHz	100 MT/s	2.5	128 KiB	8.8 W	2.7—2.9 V	Super Socket 7 CPGA 296
WinChip 3-333	266 MHz	100 MT/s	2.66	128 KiB	9.3 W	2.7—2.9 V	Super Socket 7 CPGA 296

See also

• List of VIA microprocessors

References

1. "IDT WinChip 2 Processor Data Sheet for WinChip 2 version A" (PDF). January 1999. Retrieved 2 November 2011.
2. Hare, Chris. "Processor Speed Settings". Archived from the original on 28 April 2007. Retrieved 24 April 2007.
3. "IA-32 implementation: Centaur WinChip 2". SandPile.org. Archived from the original on 27 April 2007. Retrieved 29 April 2007.
4. Pabst, Thomas (9 October 1997). "The IDT WinChip C6 CPU". Tom's Hardware. Retrieved 29 April 2007.
5. Witheiler, Matthew (5 January 2001). "The New VIA Cyrix III: The Worlds First 0.15 Micron x86 CPU". AnandTech. Retrieved 29 April 2007.
6. "IA-32 implementation: Centaur WinChip". Sandpile. Retrieved 13 May 2007.
7. "IDT WinChip 2 Processor Data Sheet for WinChip 2 version B" (PDF). April 1999. Retrieved 2 November 2011.
8. "IDT WinChip 3 Processor Data Sheet" (PDF). April 1999. Retrieved 2 November 2011.

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