Cyrix processor chips: In memoriam

Cyrix was a scrappy, up and coming CPU manufacturer in the 1990s. They never had Intel’s name recognition, but for a few years they made life more difficult for its larger rivals, Intel and AMD. For a while, Cyrix processor chips were a popular choice for value-conscious PC buyers.

Cyrix contributed a lot of confusing alphabet soup to the 1990s CPU market, and their chips usually weren’t the highest-performing chips available. But they usually did provide good value for the money, even though Cyrix never was a premium brand.

More than the 6×86

Cyrix processor: MediaGX
The Cyrix MediaGX processor wasn’t as famous as the 6×86 but enjoyed a long life on the market as an entry-level and embedded CPU.

The 6×86 CPU was the chip that really put Cyrix on the map, but Cyrix had products before the 6×86.

Cyrix was founded in 1988 by Jerry Rogers and Tom Brightman in Richardson, Texas, a suburb of Dallas. Its first chip, released in 1989, was a 387-compatible math coprocessor that was up to 50% faster than Intel’s chip while costing less. Rogers assembled a team of 30 engineers, most of whom came from Texas Instruments. This TI pedigree led some pundits to speculate in the early 1990s that Cyrix might have been a front for TI to lower the risk of competing with Intel. TI’s and Cyrix’s own troubled relationship put an end to that speculation after 1993.

Cyrix launched its IPO in 1993 at $13 per share, and quickly jumped to $19 per share. And by the end of 1993, Cyrix had captured 5 percent of the CPU market.

The Cyrix 486SLC and 486DLC

The first Cyrix CPU chips were the 486SLC and 486DLC CPUs, which were pin-compatible with the 386, not the 486, and could use the 387 math corprocessors. They had the 486 instruction set and a small 1K cache, so they outperformed the 386, but couldn’t really keep pace with an Intel 486 with its larger cache and more efficient data bus. Then again, Cyrix sold its 40-MHz version for $199, when Intel charged $404 for a chip clocked at 33 MHz.

The SLC and DLC CPUs mostly found use in off-brand PCs, from small companies who didn’t mind taking a chance on an unknown CPU maker. They ran at 25, 33, and 40 MHz. The SLC was really only a 486-class machine in name only. The DLC chip tended to perform one speed grade back from a comparable Intel chip. Since they plugged into 386 sockets, integrators could use 386 motherboards with Cyrix CPUs to deliver very low-cost PCs.

Intel sued Cyrix, but since other companies who had patent cross-licenses with Intel made the chips, Intel’s suit was unsuccessful. Over the course of its history, Intel sued Cyrix 17 times, though Cyrix always won in court.

In 1993, Cyrix also released an upgrade CPU that plugged into a 386 socket, providing a clock-doubled 486-compatible CPU. While a 386 upgraded with one of Cyrix’s upgrade chips had limitations, it did bring aging 386 systems into 486-class territory.

The Cyrix 486

By 1993, Cyrix released full 486-class chips that were fully pin-compatible with Intel and AMD 486s. Unlike AMD’s design, which was derived from Intel’s design, Cyrix’s 486 was a clean-room implementation. The Cyrix 486s were about 10 percent slower than an Intel or AMD counterpart, but they were cheap. They also made a cheap alternative to an Intel DX2 Overdrive CPU since they ran at 5 volts. AMD CPUs couldn’t run at 5 volts as part of their settlement with Intel. But you could buy a Cyrix DX2 for half the price and get 90 percent of the benefit.

The Cyrix 5×86

Cyrix also released an oddball 5×86 CPU in August 1995. This was really a throwback to the 486DLC, in that it wasn’t really a 586-class CPU. It had a 486 data bus with a 4x clock multiplier and some advanced fifth-generation features, such as branch prediction, but it didn’t have the full Pentium instruction set. Cyrix only sold the chip for about six months, discontinuing it when the 6×86 was ready for market.

The Cyrix 6×86/M II series

The Cyrix 6×86 was a revolutionary CPU for its time, offering about 30% better performance than a Pentium, at least when it came to integer performance. But Cyrix used its controversial “P-rating,” selling 133 MHz chips as equivalent to Intel 166 MHz parts. This could be deceptive, because the motherboard you used could affect the overall performance, and the Cyrix chip’s math performance was nowhere near Intel’s. The Cyrix chip was indeed fantastic for word processing and e-mail, but it wasn’t as good as an Intel or AMD CPU for 3D gaming.

The Cyrix chips sold well at first, but once it became apparent they weren’t a good choice for high-performance gaming, Cyrix lost popularity quickly. Compaq used their chips, as they were sympathetic to any alternative to Intel, and Packard Bell used them in its least expensive machines.

Ultimately Cyrix released three major variants of the 6×86: the initial design, the lower-voltage 6x86L, and the 6x86MX which added MMX instructions. The 6×86, later renamed the M II, couldn’t scale in clock speed like Intel and AMD, and adding more cores wasn’t really an option in the Windows 95 and 98 days, so Cyrix had to find other ways to try to compete.

The MediaGX series

Once it was clear Cyrix wouldn’t match Intel and AMD for performance, it created a highly integrated CPU called the MediaGX that was essentially a system-on-a-chip. Released in 1997, it offered entry-level Pentium performance at best, but by using the 5×86 CPU core along with integrated graphics and sound, it allowed for very compact and inexpensive machines. It found use in subcompact laptops and very low-end desktop machines, usually available during the back-to-school season.

Fabless before fabless was cool

When Jerry Sanders ran AMD, he famously said, “Real men have fabs,” when comparing his company to Cyrix. AMD didn’t have as much manufacturing capacity as Intel, but they did have their own. Cyrix did not, so Cyrix designed its CPUs, then relied on other companies to manufacture them. At various times in its existence, Cyrix used Texas Instruments and SGS-Thomson (later ST Microelectronics) as contract manufacturers. In 1994, Cyrix added IBM as a third manufacturer. As part of their agreement, these companies could make the chips themselves and sell them under their own brand name. But this meant Cyrix frequently found itself competing with its own product.

Cyrix and TI traded lawsuits, with TI alleging breach of contract and Cyrix alleging TI didn’t give it enough manufacturing capacity. The two companies settled, with TI paying Cyrix and licensing its technology. Cyrix turned to IBM and ST to get the capacity it needed. Unfortunately for Cyrix, ST had difficulty making the 6×86 line of CPUs reliably, so most of the 6×86 CPUs were made by IBM.

Oddly, IBM chose to sell its share of the 6×86 chips on the open market rather than use them in its own PCs, even though IBM was never shy about busting Intel’s chops when problems occurred in its chips. IBM-branded 6×86 chips often sold at a slight discount compared to its Cyrix counterparts, although they were identical except for who’s name was etched on the top.

The end of the line for Cyrix

The legal wrangling with Intel and TI and the difficulty in securing manufacturing capacity took its toll. In 1997, National Semiconductor purchased Cyrix although production had to remain at IBM. Cyrix’s chip line didn’t thrive under National Semiconductor, however, and Natsemi never successfully transitioned production to its own fab in Portland, Maine. In 1999, Natsemi sold Cyrix to VIA Technologies but retained the MediaGX series, which it continued to sell as the Geode line. Natsemi sold the Geode to AMD in 2003, who used it in embedded applications, such as thin clients and industrial control systems. The AMD Geode GX and LX CPUs were based on Cyrix technology.

VIA acquired the design team for IDT’s x86-compatible CPUs around the same time it acquired Cyrix from Natsemi. Cyrix had better name recognition, so VIA discontinued the Cyrix design but branded the IDT-derived chips as VIA Cyrix. The VIA Cyrix chips competed successfully with AMD’s Geode GX and LX CPUs, which were derived from Cyrix technology.

Cyrix’s legacy

In 1993, Cyrix was selling its 40 MHz 486DLC CPU with a 387 coprocessor for $199. By the time Cyrix sold out to National Semiconductor, you could buy a whole computer for $399. Cyrix was much more aggressive than either of its two larger competitors at driving prices down. The 6×86 line gave Intel a bit of competition at the high end for a time, but Cyrix really was the king of good-enough CPUs.

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