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Cyrix

From Alfawiki
Cyrix Corporation
Company typePrivate
IndustryMicroprocessors
Founded1988 in Richardson, Texas, United States
FounderTom Brightman, Jerry Rogers
DefunctNovember 11, 1997 (1997-11-11)
FateMerged with National Semiconductor
Headquarters
Richardson
,
United States
Area served
Worldwide
Key people
Terry Rogers (CEO and president until December 1996)
ProductsMicroprocessors (Cx486SLC, Cx486DLC, 5x86, 6x86, MediaGX, etc.)
ParentNational Semiconductor (from 1997)

Cyrix Corporation was established in 1988 in Richardson, Texas as a developer of microprocessors, initially focusing on floating point units compatible with Intel's 286 and 386 CPUs. The founders were Tom Brightman and Jerry Rogers. Terry Rogers held the roles of CEO and president until December 1996, after which he continued to contribute as a member of the Board of Directors.

In 1992, Cyrix introduced its own line of i386-compatible processors, namely the 486SLC and 486DLC models, which delivered superior performance compared to Intel's offerings while being more affordable. These processors were aimed primarily at users seeking to upgrade their existing hardware. Their launch, however, led to significant legal battles with Intel. Meanwhile, IBM, which served as Cyrix’s manufacturing partner, sold identical designs under its own branding.

Due to financial strain from these legal conflicts, Cyrix merged with National Semiconductor on November 11, 1997. National Semiconductor continued the processor series under the MediaGX name, which eventually evolved into the Geode family by 1999. In 2003, National Semiconductor transferred ownership of the Geode line to AMD, who maintained production until discontinuing it in 2019.

History

At the close of March 1992, Cyrix released the Cyrix Cx486SLC, an x86 processor compatible by pin layout with the 386SX and optimized for notebook computers. This was followed in June 1992 by the Cx486DLC, a desktop variant compatible with the 386DX.

Cyrix FasMath coprocessors

The initial personal computer product from Cyrix was an x87-compatible floating point unit (FPU) coprocessor launched in November 1989. The FasMath 83D87 and 83S87 models were pin-compatible replacements for Intel’s 80387 and 80387SX respectively, offering up to a 50% increase in performance alongside reduced power consumption during idle states. These were available in 16 MHz and 20 MHz versions priced at $506 and $556. Additionally, the FasMath 82S87—a chip compatible with the 80287 and derived from the 83D87—was introduced in 1991.

486

Among Cyrix’s early CPU offerings were the 486SLC and 486DLC, both launched in 1992. Although their names referenced the 486 series, these processors were pin-compatible with the earlier 386SX and DX sockets respectively. They provided performance that fell between Intel’s 386 and full-fledged 486 processors by incorporating on-chip L1 cache and supporting the 486 instruction set. These chips primarily served as upgrade solutions for older 386 systems and gained popularity among resellers converting slow-moving 386 motherboards into budget-friendly 486-class machines. Despite facing criticism for not meeting performance expectations suggested by their names and causing confusion with Intel’s SL and IBM’s SLC product lines, these processors found a niche in cost-effective PC clones and laptop computers.

Subsequently, Cyrix launched clock-doubled versions—the Cyrix 486SRX2 and 486DRX2—intended as consumer upgrades from the 386 to the 486 architecture. These featured internal cache coherency mechanisms that enhanced compatibility with legacy motherboards lacking advanced cache control.

Eventually, Cyrix introduced pin-compatible models such as the Cx486S and Cx486DX, entering the market later than AMD’s equivalents. Performance benchmarks placed these slightly behind comparable AMD and Intel processors, positioning them primarily within budget-conscious upgrade markets. Unlike AMD, which secured original equipment manufacturer (OEM) partnerships with companies like Acer and Compaq, Cyrix mainly catered to users upgrading existing systems. Their CPUs operated at a voltage of 5 V compared to AMD’s standard of 3.3 V, allowing compatibility with early-generation 486 motherboards and supporting their strategy focused on business expansion through upgrade opportunities.

Cyrix 5x86

In 1995, prior to the availability of its Pentium-compatible processor, Cyrix introduced the Cyrix Cx5x86 (M1sc), a streamlined variant of the high-end 6x86 (M1). Designed to fit into a 3.3V 486 socket, it operated at clock speeds of 80, 100, 120, or 133 MHz and delivered performance on par with a 75 MHz Pentium. Similar to Intel's Pentium Overdrive, the Cyrix 5x86 utilized a 32-bit external data bus and incorporated features reminiscent of the Pentium architecture, setting it apart from AMD’s Am5x86, which was essentially a 486 processor with a quadrupled clock rate.

Cyrix 6x86

Later that same year, Cyrix launched its flagship processor, the Cyrix 6x86 (M1), which gained recognition for outperforming Intel’s comparable Pentium models despite operating at lower frequencies. Marketed under designations such as P166+ to emphasize its superior performance relative to a 166 MHz Pentium, the 6x86 initially carried a premium price tag. However, its floating-point unit lagged behind Intel’s due to less advanced instruction pipelining.

The emergence of first-person 3D gaming highlighted certain limitations; notably, id Software’s Quake optimized for the Pentium’s pipelined FPU to enhance perspective correction during texture mapping—an optimization absent in Cyrix’s design. This resulted in competitive pressure leading Cyrix to reduce prices. Although the 6x86 found favor among enthusiasts and smaller retailers, it failed to gain significant traction with major original equipment manufacturers. The game-specific optimizations favoring Pentium chips reinforced Intel’s dominance in the gaming CPU sector, underscoring the difficulties Cyrix faced in this key market segment.

Cyrix 6x86L and 6x86MX

The 6x86L was introduced as an energy-efficient variant of the original 6x86, while the 6x86MX (M2) incorporated MMX instruction support along with an expanded L1 cache. The Cyrix MII, derived from the 6x86MX architecture, primarily served as a rebranding strategy aimed at enhancing competitiveness against Intel’s Pentium II processors.

Cyrix MediaGX

In 1996, Cyrix unveiled the MediaGX processor, which integrated essential PC components such as audio and video controllers onto a single chip. Initially based on the 5x86 core running at either 120 or 133 MHz, its performance was modest but its affordability drove widespread adoption. Compaq selected MediaGX for its entry-level Presario 2100 and 2200 series, which subsequently led to sales to Packard Bell and eMachines, bolstering Cyrix’s reputation in the marketplace. Subsequent iterations of MediaGX achieved clock speeds up to 333 MHz and added MMX capabilities alongside enhanced video functionality.

Cyrix Media GXi, Jedi, and Gobi Cayenne

Cyrix developed the Cayenne core as an advancement of the 6x86MX/MII line, featuring a dual-issue floating-point unit, support for 3DNow instructions, and an integrated 256 KB on-chip L2 cache. Intended for deployment across various products—including a successor to MediaGX codenamed Jedi—the focus later shifted toward producing a Socket 370-compatible CPU known as Gobi. The Media GXi launched in early 1997 targeted mobile computing markets with clock speeds ranging from 120 to 180 MHz and integrated graphics and audio controllers tailored for compact notebook systems. Later that year marked Cyrix’s acquisition by National Semiconductor.

Cyrix M3 Jalapeño

The Jalapeño core represented a fresh architectural design incorporating a dual-issue floating-point unit, register renaming capabilities, out-of-order execution within an 11-stage pipeline, and an advanced on-die L2 cache sized at 256 KB. Its floating-point subsystem included two independent FPU/MMX units equipped with fully pipelined x87 adders and multipliers supporting both MMX and 3DNow instruction sets. The processor featured an integrated Rambus memory controller delivering bandwidth up to 3.2 GB/s to minimize latency and contained built-in 3D graphics hardware capable of rendering up to three million polygons per second at a clock speed of 233 MHz. The graphics engine utilized the CPU’s L2 cache for texture storage. Target frequencies ranged between 600 and 800 MHz with scalability beyond one gigahertz planned; production was scheduled for late 1999 using a 0.18-micron fabrication process with an estimated die size of approximately 110–120 mm².

Following VIA Technologies’ acquisition of Cyrix from National Semiconductor, development of Jalapeño became uncertain as VIA discontinued this project while continuing production of late-generation Cyrix processors under the VIA Cyrix III (Cyrix 3) brand name.

PR system

Since the 6x86 processor delivered superior instructions-per-cycle efficiency compared to Intel's Pentium and occasionally operated with faster bus speeds, Cyrix and AMD jointly introduced the contentious Performance Rating (PR) scheme to facilitate more accurate product comparisons against Intel's offerings. For instance, a 6x86 running at 133 MHz typically outperformed a Pentium at 166 MHz in benchmarks, leading to the marketing of the 133 MHz 6x86 as the 6x86-P166+. Following legal challenges from Intel over using "P166" and "P200" designations for non-Pentium CPUs, Cyrix appended an "R" to its product names.

The PR system stirred debate because Cyrix processors excelled in productivity tasks but fell behind in floating-point calculations, which affected performance in newer gaming titles. Moreover, Cyrix’s positioning as a cost-effective option meant that overall system performance could be inferior compared to Pentium-based setups equipped with higher-tier components.

AMD initially adopted PR ratings for its early K5 models but discontinued this approach with the K6 series, only to bring back a similar concept later with the Athlon XP line.

Manufacturing partners

Operating as a fabless semiconductor company, Cyrix focused on CPU design while contracting manufacturing to external foundries. Early production runs were handled by Texas Instruments and SGS Thomson (now STMicroelectronics). The Richardson office of VLSI Technology provided early design support through specialized tools and expertise. In 1994, following conflicts with TI and manufacturing difficulties at SGS Thomson, Cyrix established a partnership with IBM Microelectronics, whose fabrication capabilities were competitive with Intel’s.

This collaboration granted IBM rights to manufacture and market Cyrix-designed processors under its own brand. Although intended to expand Cyrix’s market reach, IBM predominantly continued sourcing CPUs from Intel and AMD, incorporating Cyrix chips only in select low-cost systems outside the United States. Additionally, IBM independently sold 6x86 processors, occasionally competing directly with Cyrix by offering lower prices.

Legal troubles

Unlike AMD, Cyrix never produced or sold Intel-designed CPUs under license agreements. Instead, it developed its processors through meticulous in-house reverse engineering, creating independent designs that often advanced technology while maintaining compatibility with Intel sockets. For example, Cyrix’s initial product—the 8087 math co-processor—featured hardware multipliers that delivered faster and more precise operation than Intel’s equivalent.

Intel launched numerous lawsuits against Cyrix alleging patent violations related to its 486 architectures. Nonetheless, courts consistently ruled in favor of Cyrix across various federal and state cases, confirming their right to manufacture x86 CPUs through any foundry licensed by Intel. To prevent antitrust litigation from Cyrix, Intel agreed to a $12 million settlement and granted licenses for patents previously asserted against Cyrix. This arrangement enabled Cyrix to produce chips via foundries such as SGS Thomson and IBM.

In a reversal during litigation in 1997, Cyrix accused Intel’s Pentium Pro and Pentium II processors of infringing on its patents concerning power management and register-renaming technologies. This dispute concluded rapidly through cross-licensing agreements that allowed both companies unrestricted access to each other’s patent portfolios without any admission of infringement.

Merger with National Semiconductor

In August 1997, during ongoing legal disputes, Cyrix combined operations with National Semiconductor, gaining enhanced marketing capabilities and access to National’s manufacturing facilities originally designed for RAM and telecommunications hardware. This union strengthened Cyrix’s financial footing and development resources, as chip production transitioned from IBM’s plants to those of National.

Following the merger, National Semiconductor shifted focus toward cost-effective single-chip solutions like the MediaGX, deprioritizing Cyrix’s more advanced processors such as the 6x86 and MII series. The MediaGX was aimed at OEMs striving to minimize PC expenses, representing a more secure position in a market uncertain about competing with Intel’s high-performance offerings.

Nevertheless, National Semiconductor soon encountered financial setbacks that adversely affected Cyrix. By 1999, while AMD and Intel rapidly increased processor clock speeds, Cyrix faced challenges improving the MII line due to technical complications, including a non-standard 83 MHz bus that caused instability on numerous motherboards. Additionally, the 6x86 CPUs produced excessive heat and suffered compatibility problems with widely used sound cards. At the same time, MediaGX contended with intense competition from increasingly affordable budget processors from Intel and AMD. Once recognized as a performance-focused brand, Cyrix gradually shifted toward entry-level segments, risking obsolescence.

The last processor bearing the Cyrix name was the MII-433GP operating at 300 MHz. Although it surpassed an AMD K6/2-300 in floating-point unit (FPU) performance, it was frequently unfavorably compared to true 433 MHz chips from rivals—a significant marketing hurdle.

Eventually, National Semiconductor withdrew from the CPU business, resulting in the departure of many Cyrix engineers. When VIA Technologies acquired Cyrix, the original design team had disbanded and the MII series had become outdated. VIA continued utilizing the Cyrix brand for processors developed by Centaur Technology, capitalizing on Cyrix’s stronger market presence.

Glenn Henry, CEO of Centaur Technology, reflected on Cyrix’s downfall: "Cyrix had a solid product line but was acquired by a large ‘smokestack’ company and became bloated. When VIA purchased Cyrix, they had 400 employees; we had 60 and were producing more."

National Semiconductor retained and rebranded MediaGX as the Geode, targeting integrated processor markets before selling it to AMD in 2003. In 2006, AMD introduced an ultra-low-power x86-compatible processor based on the Geode core, illustrating the enduring influence of Cyrix’s architecture on energy-efficient CPU designs.

Legacy

Although Cyrix's existence was brief and its brand is no longer active, its rivalry with Intel contributed significantly to establishing the budget CPU segment. This competition helped reduce PC costs and prompted Intel to launch its Celeron series while accelerating price reductions on higher-end processors.

VIA Technologies’ acquisition of Cyrix’s intellectual property and licensing agreements provided strategic advantages in countering legal challenges from Intel, even after VIA ceased using the Cyrix brand.

In popular media

The motion picture Eraser included a fictional defense company called "Cyrex." Due to concerns over potential trademark confusion, the actual Cyrix corporation reached out to the filmmakers, prompting a digital alteration of the name to "Cyrez."

Within the machinima series Freeman's Mind, Ross Scott’s depiction of Gordon Freeman from the Half-Life universe delivers a comedic critique of Cyrix processors in the third episode.

References


External links

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