Cyrix III
Encyclopedia
Cyrix III is an x86-compatible Socket 370
CPU
. VIA Technologies
launched the processor in February 2000. VIA had recently purchased both Centaur Technology
and Cyrix
. Cyrix III was to be based upon a core from one of the two companies.
. This CPU core was a typical Cyrix design: superscalar
with speculative execution
and a high IPC rate
but rather low clock rates. To emphasize the higher performance of their designs compared to the competitors' offerings, Cyrix used a system with a "P-Rating" higher than the clock rate. The floating point
unit of the processor had supposedly been updated from the lacklustre unit in the 6x86/MII series. When the chip reached reviewers, the weighted integer/floating-point performance was found to be fairly low compared to the competition. The fact that Cyrix 6x86-line were only 486-compatible, not 100% Pentium-compatibile, intensified the negative attention at this point.
. The Samuel core was a simpler design, being an evolution of the WinChip
processors (the unreleased WinChip 4). Samuel was designed for higher clock speeds, with more L1 cache (but no L2), and used smaller manufacturing technology. While this version of Cyrix III still had sub-par performance compared to the competition from Intel and AMD, it was quite power efficient and consisted of only half the number of transistors of Cyrix's creation.
VIA dropped the criticized PR rating with new processors based on the Samuel core, in favor of simply distinguishing them by their actual clock speed.
, as it was not built upon Cyrix technology at all.
Socket 370
Socket 370 is a common format of CPU socket first used by Intel for Pentium III and Celeron processors to replace the older Slot 1 CPU interface on personal computers. The "370" refers to the number of pin holes in the socket for CPU pins...
CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
. VIA Technologies
VIA Technologies
VIA Technologies is a Taiwanese manufacturer of integrated circuits, mainly motherboard chipsets, CPUs, and memory, and is part of the Formosa Plastics Group. It is the world's largest independent manufacturer of motherboard chipsets...
launched the processor in February 2000. VIA had recently purchased both Centaur Technology
Centaur Technology
Centaur Technology is an x86 CPU design company, now a wholly owned subsidiary of VIA Technologies, a member of the Formosa Plastics Group, Taiwan's largest industrial conglomerate.-History:...
and Cyrix
Cyrix
Cyrix Corporation was a microprocessor developer that was founded in 1988 in Richardson, Texas as a specialist supplier of high-performance math coprocessors for 286 and 386 microprocessors. The company was founded by former Texas Instruments staff members and had a long but troubled relationship...
. Cyrix III was to be based upon a core from one of the two companies.
Joshua
The pre-release Cyrix III CPUs were based upon a 22 million transistor Joshua core designed by CyrixCyrix
Cyrix Corporation was a microprocessor developer that was founded in 1988 in Richardson, Texas as a specialist supplier of high-performance math coprocessors for 286 and 386 microprocessors. The company was founded by former Texas Instruments staff members and had a long but troubled relationship...
. This CPU core was a typical Cyrix design: superscalar
Superscalar
A superscalar CPU architecture implements a form of parallelism called instruction level parallelism within a single processor. It therefore allows faster CPU throughput than would otherwise be possible at a given clock rate...
with speculative execution
Speculative execution
Speculative execution in computer systems is doing work, the result of which may not be needed. This performance optimization technique is used in pipelined processors and other systems.-Main idea:...
and a high IPC rate
Instructions Per Cycle
In computer architecture, instructions per clock is a term used to describe one aspect of a processor's performance: the average number of instructions executed for each clock cycle...
but rather low clock rates. To emphasize the higher performance of their designs compared to the competitors' offerings, Cyrix used a system with a "P-Rating" higher than the clock rate. The floating point
Floating point
In computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...
unit of the processor had supposedly been updated from the lacklustre unit in the 6x86/MII series. When the chip reached reviewers, the weighted integer/floating-point performance was found to be fairly low compared to the competition. The fact that Cyrix 6x86-line were only 486-compatible, not 100% Pentium-compatibile, intensified the negative attention at this point.
Samuel
Because the Joshua core was such a mixed result in thermal output, core size, and performance, VIA switched almost immediately to an 11 million transistor Samuel core designed by Centaur TechnologyCentaur Technology
Centaur Technology is an x86 CPU design company, now a wholly owned subsidiary of VIA Technologies, a member of the Formosa Plastics Group, Taiwan's largest industrial conglomerate.-History:...
. The Samuel core was a simpler design, being an evolution of the WinChip
WinChip
The WinChip series was a low-power Socket 7-based x86 processor designed by Centaur Technology and marketed by its parent company IDT.-Design:The design of the WinChip was quite different from other processors of the time...
processors (the unreleased WinChip 4). Samuel was designed for higher clock speeds, with more L1 cache (but no L2), and used smaller manufacturing technology. While this version of Cyrix III still had sub-par performance compared to the competition from Intel and AMD, it was quite power efficient and consisted of only half the number of transistors of Cyrix's creation.
VIA dropped the criticized PR rating with new processors based on the Samuel core, in favor of simply distinguishing them by their actual clock speed.
Samuel 2
The Samuel 2 core is a revision to the Samuel core. The Centaur Technology team added an on-die 64 KiB L2 cache and moved to a 150 nm manufacturing process. These changes improved per-clock performance, reduced power demands, and increased clock speed scalability.Renamed
The VIA Cyrix III was later renamed VIA C3VIA C3
The VIA C3 is a family of x86 central processing units for personal computers designed by Centaur Technology and sold by VIA Technologies. The different CPU cores are built following the design methodology of Centaur Technology.-Samuel 2 and Ezra cores:...
, as it was not built upon Cyrix technology at all.