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Intel's strongest competitor in history: not AMD

via:驱动之家     time:2020/11/27 14:41:51     readed:815

There is no doubt that most people are familiar with Intel and AMD、 Qualcomm (Qualcomm), Texas Instruments (Texas Instruments), and even VIA

For most of the past decade, Cyrix has managed to bring the personal computer into the homes of ordinary people cheaply, but it was shut down by its best product and its inability to run a popular game, and it was acquired by a larger partner.

The early 1990s was a strange time for the desktop computer industry, especially for the microprocessor world.

Despite the fierce competition in the field of processors, Intel still seems to be the winner. At that time, apple switched to IBM's PowerPC, and Motorola's 68K chip was slowly dragging Commodore's Amiga PC family to a dead end. Arm was just a small flame ignited by apple, VLSI technology and acorn computer company, which at that time focused almost entirely on the development of suitable processors for the notorious Newton.

About the same time, AMD took the lead in taking the first step to get rid of the negative aura that is considered a second supplier. AMD launched its own architecture after cloning several generations of intel CPU, which by the late 1990s had been well recognized for price and performance.

This success can be attributed at least in part to Cyrix, which had a chance to dominate the home PC market and kick Intel and AMD out of the game. Unfortunately, Cyrix failed to succeed and quickly disappeared among a number of technology companies.

See little know

Founded in 1988 by Jerry Rogers and Tom Brightman, Cyrix was initially a manufacturer of high-speed x86 math coprocessors for 286 and 386 processors.

They're talented people from Texas Instruments, and they have great ambition to fight Intel and try to beat Intel on their own track. Rogers began to actively seek the best engineers in the United States, but later became a notorious, tough leader, leading a team of 30 people, undertaking impossible tasks.


At first, the company's first batch of mathematical coprocessors outperformed Intel's peers by about 50% in performance and at a lower price. This makes it possible to combine amd 386 CPU with Cyrix fastmath coprocessor, and obtain 486 like performance at a lower price. This has attracted the attention of the industry and encouraged Rogers to take the next step to enter the CPU market.

1992, Cyrix launched the first CPU, SLC 486 and DLC,486 aims to compete with Intel 486 SX and 486 DX. They are also compatible with the 386 SX and 386 DX pins, This means they can be used as embedded upgrades to the old 386 motherboard, And manufacturers also use them to sell cheap laptops.


The performance of both products is slightly worse than that of Intel 486 CPU, but its performance is much better than that of 386 CPU. Cyrix 486 DLC cannot compete with Intel 486sx clock rhythm, but it is a full 32-bit chip with 1KB L1 cache and much lower cost.

At that time, enthusiasts liked the fact that they could use 486dlc to run at 33 MHz to achieve performance comparable to Intel 486sx running at 25 MHz.

This is not to say that it is not without problems, because it may cause stability problems on some old motherboards, which do not have additional cache control lines or CPU register controls to enable or disable on-board caching.


Cyrix also developed a Cx486DRu2 name


Cyrix and intel finally reached an out-of-court settlement, and intel agreed that Cyrix had the right to produce its own x86 designs at factories holding intel cross-licensing, such as texas instruments, IBM and later italian semiconductors).

Never repeat the same trick twice

In 1993, Intel launched the original Pentium processor based on P5 micro architecture, and finally became famous for its market friendly name. But more importantly, it raises the threshold of performance, thus ushering in a new era of personal computing.

The superscalar architecture allows it to complete two instructions per clock. A 64 bit external data bus enables each memory access to read and write more data. Faster floating-point units can achieve 15 times the throughput of 486 FPU. There are other advantages.

Cyrix again faces the challenge of creating a middle ground for the socket 3 motherboard of the new Intel Pentium CPU until the model is ready to ship. The intermediate point is Cyrix 5x86, which at 75 MHz has many of the features of fifth generation processors such as Pentium and AMD K5.

The company even makes 100 MHz and 133 MHz versions, but they don't really have all the enhanced performance features mentioned in the promotion, because if enabled, they can lead to instability and the overclocking potential is limited. All of these products were short-lived, and six months later Cyrix decided to stop selling them and switch to other processor designs.

Cyrix through Thor's hammer

In 1996, Cyrix launched a 6x86 (M1) processor, which is expected to replace the old Intel CPU on the socket 5 and socket 7 motherboards with good performance. But it was not only a way to upgrade the budget system, but it actually made CPU design somewhat miraculous, which was considered impossible at that time - it combined many design aspects of RISC core and CISC.

At the same time, it continues to use native x86 execution and ordinary microcode, while Intel's Pentium pro and AMD K5 rely on dynamic conversion to micro ops. Cyrix 6x86 is compatible with Intel p54c pins and has six variants and confusing naming schemes that should indicate the expected level of performance, but not an actual indicator of clock speed.

x86PR166 6, for example, runs only on 133 MHz and is marketed as the same or better Pentium to run on 166 MHz, a strategy that AMD will adopt later.


The problem is that Intel will not be able to fully identify its own x86 instruction set, though. Most applications that exploit more compression in P5 will slow down the development of new applications due to their slow performance.

Cyrix eventually improved compatibility with Pentium and Pentium Pro through 6x86 MX and 6x86 MII. One of the big selling points of 6x86 is that its integer performance is significantly better than Pentium's, which is a good advantage when most applications and games rely on integer operations.

For a while, Cyrix even tried to charge extra for the added performance, but soon the strategy failed.

Cyrix 6x86 MX CPU chip diagram results show that the 6x86 FPU (floating point unit) is only a slightly modified version of Cyrix's 80387 coprocessor, so it is much slower than the new FPU design integrated by Intel's Pentium and Pentium pro.

To be fair, it's still two to four times faster than the Intel 80486 FPU, while the Cyrix 6x86 outperforms Intel in overall performance. However, when many software developers, especially those who make 3D games, see Pentium becoming more and more popular and choose to optimize their code with assembly language around the advantages of P5 FPU, the whole balance breaks down.


When id software released quake in 1996, gamers with 6x86 processors found that they could get a standard frame rate of up to 15 frames per second and could not be played unless they wanted to reduce the resolution to 320 x 200. Only the most advanced Cyrix 6x86 MX PR2 / 200 CPU can achieve 29.7 FPS playability. But gamers using Intel have no problem running games at 640 x 480 playable frame rates.

John Carmack found that he could overlap integer and floating-point operations on a Pentium chip, because all operations of the P5 core use different parts except for instruction loading. This technology does not work on the Cyrix kernel, exposing the weakness of its FPU.

The reviewers at the time found that in all other benchmarks or performance tests, the 6x86 CPU would be 30% to 40% higher than the Pentium. As early as the mid-1990s, no one knew the exact direction of computing. Cyrix thought that integer performance was the best priority, so it produced a processor without an instruction pipeline, which would become an essential part of any processor.

Instruction pipelining is a technique for dividing tasks into a set of smaller operations that are then executed simultaneously by different parts of the processor in a more efficient manner. The FPU of Pentium processor is pipelined, which makes the processing delay of floating-point operation very low. The problem itself is easy to solve, and software developers have released patches for their applications and games.

But id software has spent too much time designing quake around P5 microarchitecture, and has never provided such a fix. AMD's K5 and K6 CPUs perform slightly better than Cyrix, but they are still not as good as Intel's on quake.

Thor's hammer is a very popular game and the flagship of a new generation of 3D games.This makes the performance gap between Cyrix CPUs very harsh, and the company has almost lost credibility in the eyes of many enthusiasts.It was a particularly heavy blow when Cyrix's fierce customer base was made up of these fanatics, as the company was unable to sign contracts with large pcoems.

To make matters worse, Cyrix is a fabless chip manufacturer that relies on third parties to make its processors, and these companies use the most advanced product lines for their own products.

the result is that the Cyrix processor is manufactured on 600 nm process nodes, while the Intel processor is manufactured on 300 nm. Efficiency is greatly affected, which is why Cyrix CPU become very hot

The fall of the first real competitor of Intel CPU hegemony

By 1997, Cyrix made every effort to establish partnerships with companies such as Compaq and HP, because integrating its CPU into the system would generate a stable source of revenue.

It also tried to sue Intel for infringement of its patents on power management and registration renaming technology, but the matter was quickly resolved through cross licensing agreements so that the two companies could continue to focus on producing better CPUs.

The famous national semiconductor advertising lawsuit has caused losses to a company that is already short of funds. Facing the prospect of bankruptcy,Cyrix agreed to merge into national semiconductor.This is really a blessing, because it will eventually be able to use the right manufacturing plants and a strong marketing team to be able to get a lot of orders.

IBM's manufacturing agreement was suspended for some time, but Cyrix eventually moved all production to national semiconductor.

However, it turns out that the acquisition will kill Cyrix. National semiconductor is not interested in manufacturing high-performance PC components, but wants to use low-power SOC (system on chip).

Sure enough, Cyrix launched the much maligned 5x86 mediagx, which integrates audio, video and memory controllers with a 5x86 core running at 120 or 133 MHz. Its performance is poor, but it convinced Compaq to use it in its low-end Presario computers. This has inspired other OEMs to demand 6x86 CPUs, such as Packard bell and emachines.


The shift in focus didn't stop Cyrix from trying to produce more high-performance CPUs, but it brought hope and other goals.National Semiconductor eventually sold Cyrix to via technologies, a Taiwanese chipset maker, but by then the key players had left, and MII CPU became a worthless part and no buyer was found

The last design of Cyrix is the mii-433gp, which runs in a 300 MHz environment. Due to this unfortunate naming scheme, it finally compares with a processor running at 433 MHz, which performs much better.

AMD and Intel are running for GHz or more bandwidth, and it will take two decades for Arm to challenge the giants in the desktop and server markets

Via replaced Centaur's brand with the name Cyrix, which is its last poison tooth, because its processor actually uses the winchip3 core designed by IDT. National Semiconductor continued to sell mediagx for several years until it renamed it geode in 2003 and sold its design to AMD. Three

Years later, amd demonstrated the world's lowest power x86 compatible CPU, which only needs 0.9 watts of power, and is based on the geode core, which is considered to be a proof of the originality of the Cyrix design team.

Why is Cyrix's legacy important

Whether you have a PC equipped with a Cyrix CPU or not, although the impact on the PC industry during its 10 years of existence is relatively small, the company's history and lessons are still worth remembering. Cyrix's failure has shown that improving instructions per clock is a more effective effort for processor manufacturers than increasing the original clock speed.

Until today, Intel and AMD have tried to increase the nominal clock speed of each generation, but after the 3 GHz milestone, most of the real improvements come from rethinking the core parts of their respective microarchitectures. The most famous example is AMD's Zen upgrade, which has improved single thread performance by 68% in less than four years.


Cyrix survived and overcame many of Intel's legal (broadly financial) pressures, and Intel sued almost everyone in the CPU space that existed in the 1990s. It shows twice that litigation is not conducive to a healthy market, and cross licensing transactions lead to a lot of overlapping between the engineering work of different companies, which can prove beneficial.

Unfortunately, the cross licensing agreement between AMD and Intel on X86 prevents third parties from entering the market, and the only company still trying to break the duopoly is China's Shanghai Zhaoxin. In its heyday, Cyrix was also a fabless company.

Today, this has become standard practice for most Silicon Valley giants, including AMD, Qualcomm, Broadcom, NVIDIA, apple, Marvell, Unigroup China and Hisilicon, all of which rely on other companies to make chips.

Before merging with national semiconductor, the company's marketing strategy was never very good.

In the 2000s, AMD's Athlon and Sempron processors made the same mistake. These processors are marked as faster than Intel processors, but run at lower clock speeds, but this does not always translate well in benchmark or actual performance tests. Amd gave up this plan, but it can be said that things are still a little confused today.

Today, you are unlikely to find Cyrix processors other than in the recycling business and the old computer products of enthusiasts.

There is online evidence that Cyrix based desktops won't be available until at least 2010, which means they'll be around for 10 years after the company has essentially integrated into via technology's products. Via's megaletter arm is unlikely to still use anything from the original Cyrix design, but only time will tell if they have learned a lesson to commemorate Cyrix's legacy.


#Intel#via #CPU

Link to the original text:Semiconductor industry observation

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