[permalink] [id link]
The 6x86 successor — MII — was late to market, and couldn't scale well in clock speed with the manufacturing processes used at the time.
from
Wikipedia
Some Related Sentences
6x86 and —
The FPU in the 6x86 was largely the same circuitry that was developed for Cyrix's earlier high performance 8087 / 80287 / 80387-compatible coprocessors, which was very fast for its time — the Cyrix FPU was much faster than the 80387, and even the 80486 FPU.
6x86 and MII
Therefore, despite being very fast clock by clock, the 6x86 and MII were forced to compete at the low-end of the market as AMD K6 and Intel P6 Pentium II were always ahead on clock speed.
The 6x86 and MII series did exactly this, but was more advanced ; it implemented superscalar speculative execution via register renaming, directly at the x86-semantic level.
The merger also resulted in a change of emphasis: National Semiconductor's priority was single-chip budget devices like the MediaGX, rather than higher performance chips like the 6x86 and MII.
* Cyrix 6x86 and MII
* Cyrix 6x86, an x86 architecture CPU by Cyrix also known as " MII "
6x86 and was
It has been speculated by experts that 6x86 was designed to perform well specifically on business-oriented benchmarks of the time, most notably Ziff-Davis ' Winstone benchmark.
A PR rating was also necessary because the 6x86 could not clock as high as P5 Pentium and maintain equivalent manufacturing yields, so it was critical to establish the slower clock speeds as equal in the minds of the consumer.
Similar to the AMD K5, the Cyrix 6x86 was a design far more focused on integer per-clock performance than clock scalability, something that proved to be a strategic mistake.
However, the 6x86 was the star performer in the range, giving a tangible performance boost over the Intel " equivalent ".
In fact, the 6x86 processor was clocked at a significantly lower speed than the Pentium counterpart it outperformed.
The later 6x86L was a revised 6x86 that consumed less power, and the 6x86MX ( M2 ) added MMX instructions and a larger L1 cache.
Because the 6x86 was more efficient on an instructions-per-cycle basis than Intel's Pentium, and because Cyrix sometimes used a faster bus speed than either Intel or AMD, Cyrix and competitor AMD co-developed the controversial PR system in an effort to compare its products more favorably with Intel's.
Since a 6x86 running at 133 MHz generally benchmarked slightly faster than a Pentium running at 166 MHz, the 133 MHz 6x86 was marketed as the 6x86-P166 +.
There was also a problem which made the 6x86 incompatible with the then-popular Sound Blaster AWE64 sound card.
Released in August 1995, four months before the more famous Cyrix 6x86, the Cyrix 5x86 was one of the fastest CPUs ever produced for Socket 3 computer systems.
The Cyrix 5x86 processor, codename " M1sc ", was based on a scaled-down version of the " M1 " core used in the Cyrix 6x86, which provided 80 % of the performance for a 50 % decrease in transistors over the 6x86 design.
WinChip C6 was a competitor to the Intel Pentium and Pentium MMX, Cyrix 6x86, and AMD K5 / K6.
Its floating point performance was well below that of the Pentium, being similar to the Cyrix 6x86.
Additionally, while the K5's floating point performance was better than that of the Cyrix 6x86, it was weaker than that of the Pentium.
6x86 and market
For example, a 133 MHz 6x86 will outperform a P5 Pentium at 166 MHz, and as a result Cyrix could market the 133 MHz chip as being a P5 Pentium 166's equal.
IBM instead sold its 6x86 chips on the open market, competing directly against Cyrix and sometimes undercutting Cyrix's prices.
6x86 and well
In a more modern context, the complex variable length encoding used by some of the typical CISC architectures makes it complicated, but still feasible, to build a superscalar implementation of a CISC programming model directly ; the in-order superscalar original Pentium and the out-of-order superscalar Cyrix 6x86 are well known examples of this.
6x86 and clock
Cyrix used a PR rating ( Performance Rating ) to relate their performance to the Intel P5 Pentium ( pre-P55C ), because a 6x86 at a lower clock rate outperformed the higher-clocked P5 Pentium.
6x86 and with
The 6x86 and 6x86L weren't completely compatible with the Intel P5 Pentium instruction set and is not multi-processor capable.
It had the 32-bit memory bus of an ordinary 486 processor, but internally had much more in common with fifth-generation processors such as the Cyrix 6x86, the AMD K5, and the Intel Pentium, and even the sixth-generation Intel Pentium Pro.
It is likely Cyrix could have continued to successfully sell processors based on Socket3, but canned the 5x86 so that it would not compete with its then new 6x86 offerings.
mainboards using the SiS 530 were positioned as cheap office platforms and paired often with low-cost chips from Intel competitors, such as the AMD K6 series or Cyrix 6x86.
6x86 and used
While the 6x86 quickly gained a following among computer enthusiasts and independent computer shops, unlike AMD, its chips had yet to be used by a major OEM customer.
While some in the industry speculated this would lead to IBM using 6x86 CPUs extensively in its product line and improve Cyrix's reputation, IBM continued to mostly use Intel CPUs, and to a lesser extent, AMD CPUs, in the majority of its products and only used the Cyrix designs in a few budget models, mostly sold outside of the United States.
Processors that used Socket 7 are the AMD K5 and K6, the Cyrix 6x86 and 6x86MX, the IDT WinChip, the Intel P5 Pentium ( 2. 5 – 3. 5 V, 75 – 200 MHz ), the Pentium MMX ( 166 – 233 MHz ), and the Rise Technology mP6.
6x86 and at
* Cyrix 6x86 (" M1 ") at PCGuide
The ratings were based on a limited set of benchmark suites which measured only integer performance, which the K5 and the 6x86 in particular excelled at.
6x86 and time
This wouldn't have been a big problem for the 6x86 if, by that time, Quake had a fallback to do perspective correction without the FPU like in e. g. the game Descent.
Almost all of the 6x86 line produced a large amount of heat, and required quite large heatsink / fan combos ( for the time ) to run properly.
6x86 and .
The Cyrix 6x86 ( codename M1 ) is a sixth-generation, 32-bit 80x86-compatible microprocessor designed by Cyrix and manufactured by IBM and SGS-Thomson.
A simplistic block diagram of the Cyrix 6x86 microarchitecture.
The 6x86 is superscalar and superpipelined and performs register renaming, speculative execution, out-of-order execution, and data dependency removal.
Some companies released patches for their products to make them function on the 6x86.
The first generation of 6x86 had heat problems.
Another release of the 6x86, the 6x86MX, added MMX compatibility, introduced the EMMI instruction set, and quadrupled the primary cache size to 64 KB.
Fortunately for the 6x86 ( and AMD K6 ), many games continued to be integer-based throughout the chip's lifetime.
* cpu-collection. de Cyrix 6x86 processor images and descriptions
6x86 processors were given names such as P166 + indicating a performance better than a Pentium 166MHz processor.
0.118 seconds.