AMD K6-III

• Sharptooth (K6 -III)
• Sharptooth (K6 -2 )
• Sharptooth ( K6- III )

The K6- III is an x86 microprocessor from AMD. He is one of the fastest processors available for the socket 7. On its basis, the K6 -2 and K6- III have been developed.

• 4.1 K6- III (-P) " Sharptooth " (K6 3D )
• 4.2 K6 -2
• 4.3 K6- III and K6 -IIIE

Technology

Like its predecessor, K6 -2 has also the K6- III 64 KiB L1 cache. When L2 cache was the K6 -2 but still rely on the relatively slow and not exclusively linked cache on the motherboard, which brought performance drawbacks compared to the Intel Pentium II and the Mendocino Celeron from Intel. Why AMD chose the K6- III to make the L1 cache with a full CPU clock operated and exclusively connected L2 cache on the CPU chip to the side. The K6- III downgraded the cache on the motherboard, so to speak from the L2 cache ( the AMD K6, AMD K6 -2, Cyrix 6x86 and Pentium ) to the L3 cache.

In addition, the L2 cache of the K6- III memory entries from throughout the 4 GiB can cache large address space. This is also called a Cacheable Area of 4 GiB. Due to technical and strategic market restrictions many Socket 7 motherboards and chipsets this Cacheable Area is rarely larger than 512 MiB for the caches on the motherboard, usually only 256, 128, or even - as in the case of Socket 7 chipset i430TX Intel - only 64 MiB. If the memory is expanded beyond the limits of Cacheable Area addition, the overall performance of the system still breaks the K6- 2 substantially one. Since, however, is the L3 cache when using a K6- III, the cache on the motherboard, such declines in K6- III are virtually no longer measurable.

With 21.4 million transistors of the K6- III available for the 1999 technology was a challenge. The chip was very large, and the yield correspondingly low and the operation of more than 450 MHz rarely stable possible, which is why the K6- III was also only offered with a maximum clock frequency of 450 MHz.

But Nevertheless, it sold quite well. In particular, as an upgrade CPU was the K6- III very popular, as could be achieved in some cases considerable speed improvements on older motherboards with him. The AMD was opposed by the fact that the K6- III, the multiplier setting 2 interpreted as a multiplier 6. There were also commercially special CPU adapter socket with its own voltage converters and jumpers for setting the multipliers. With the help of such intermediate base - possibly also by Tags - could be operated on almost all Socket 7 or even on Socket 5 motherboards a K6- III 400 MHz, if the BIOS is allowed. For motherboards whose producers did not support, fixed technology enthusiast this shortcoming in the BIOS so-called unofficial patches partly itself

Competition and market situation

As a competitor Intel introduced the Pentium III to the market, a revised version of the Intel Pentium II The main difference is the introduction of the instruction set KNI ( " Katmai new instruction" ), which initially operated under the name later under the name ISSE and finally only SSE was called been. As with the introduction of MMX or SSE first brought no advantage, because software, the speed advantage of this instruction set extensions could have moved, only had to be adapted or written.

Both companies tried hard to gain a clear lead. In general, the Intel CPUs at this time were superior to the floating-point calculations during the K6-III was considered to be faster in integer arithmetic. Since floating-point (Office, games) were then rarely used in standard applications, you had chosen during the design of the FPU of the K6 for a slower solution, but requires less space on the had the. Suffered from the FPU performance, what the Pentium III made ​​in scientific calculations the better choice.

With the introduction of the Athlon K6- III became obsolete. On the one hand he was no longer the AMD - top model, on the other hand claimed its production requires substantial resources: with 21.3 million transistors its production was almost as expensive as the one Athlon 22 million. Therefore, AMD drove the production capacity for the K6- III decreased significantly. The K6- III was a product hard to find.

He was finally set, but only when Intel introduced the Coppermine, an improved Pentium III CPU, the one "on- the " had cache as the Mendocino Celeron and the K6 -III. At the same time Intel moved the manufacturing process from 0.25 to 0.18 microns, which was associated with great difficulties and led to a worldwide supply shortage with Intel CPUs for more than 12 months. At that time, few manufacturers have started that had been installed only Intel CPUs, so to build Athlon systems, which auslastete the manufacturing capacity of AMD. AMD was thus forced the K6- III permanently.

K6 -2 and K6- III

At the end of the global CPU shortage developed AMD still revised versions of the K6- family: the K6 -2 and K6- III . Essentially, both processors were variants of the K6 -III ( the KiB K6 -2 128 cache, the K6- III with the full 256 KiB cache ) prepared in a new production ( 0.18-micron feature size ) and extended to "Extended 3DNow! " and " PowerNow! " CPU instructions. Although they were originally designed for notebooks, they were installed in desktop computers. In the trade these CPUs but were difficult to obtain, since they surrendered AMD primarily to system integrators and OEMs. AMD's marketing continued to focus on the Athlon, which is why these two CPUs were known mainly for experts and insiders, especially at overclockers. A popular CPU for example, was the K6- III / 450, who was often overclock to 600 MHz.

Performance

In retrospect, the K6 and its derivatives in terms of performance were a double-edged sword for AMD. Due to its slow (because running without pipeline ) floating point unit of the K6 against its direct competitor, the Intel processors Pentium MMX and Pentium II, for the FPU - intensive applications such as the then-emerging 3D games has no chance. On top of that, the Pentium II on fast L2 cache was able to draw directly on the processor module, whereas the processors of the K6 and K6- 2 series used as before the L2 cache of the ( super) Socket 7 motherboards. This bandwidth disadvantage made ​​to create the AMD CPUs, only the K6- III and the mobile variants K6 -2 and K6- III ran at the end of the K6- era thanks to the The integrated Level 2 cache in top form. These clearly show the advantages of the K6 architecture: A fast integer unit with a very short pipeline, an intelligent branch prediction unit and a very large for its time translation lookaside buffer gave it a high efficiency ( instructions per cycle). In a test against the successor - K7 architecture at the same clock speed of the K6 -2 was the winner in many integer -heavy benchmarks. However, while the only six-stage integer pipeline made ​​the K6 design largely independent of software optimizations, limited this low-latency design on the other hand significantly the maximum clock frequency: The K6 architecture reached at 570 MHz maximum, however, the K7 successor design scaled over the years to well over 2 GHz.

Model data

K6- III (-P) " Sharptooth " (K6 3D )

CPU for the desktop and the mobile segment.

• K6 -III: desktop CPU
• K6- III -P: CPU for mobile devices
• CPU ID: AuthenticAMD Family 5 Model 9
• L1 - Cache: 32 32 KiB ( Data Instructions )
• L2 cache: 256 KiB with CPU clock
• MMX, 3DNow
• Super Socket 7
• Front Side Bus: 100 MHz
• Operation voltage ( Vcore ): 2.0 to 2.4 V
• Power Consumption: 18.10 to 29.50 W
• Release Date: February 22, 1999
• Manufacturing Technology: 0.25 micron
• The size: 118 mm ² at 21.3 million transistors
• Clock rates K6 -III: 400 and 450 MHz
• K6- III -P: 333, 350, 366, 380, 400, 433, 450 and 475 MHz

Note: The 333- MHz and 475- MHz versions of the K6 - III -P are undocumented.

K6 -2

• CPU ID: AuthenticAMD Family 13 Model 5
• L1 - Cache: 32 32 KiB ( Data Instructions )
• L2 cache: 128 KiB with CPU clock
• MMX, Extended 3DNow, PowerNow!
• Super Socket 7
• Front Side Bus: 95 - 100 MHz
• Operation voltage ( Vcore ): 2.0 V
• Release Date: April 18, 2000
• Manufacturing Technology: 0.18 micron
• Clock rates: 350, 400, 450, 475, 500, 533, 550 and 570 MHz

K6- III and K6 -IIIE

CPU for the mobile and embedded segment.

• K6- III : CPU for notebooks, inter alia,
• K6 -IIIE : embedded CPU
• CPU ID: AuthenticAMD Family 13 Model 5
• L1 - Cache: 32 32 KiB ( Data Instructions )
• L2 cache: 256 KiB with CPU clock
• MMX, Extended 3DNow, PowerNow!
• Super Socket 7
• Front Side Bus: 95 - 100 MHz
• Operation voltage ( Vcore ) K6 -IIIE 1.6 V; 1.7 V; 1.8 V for "low voltage" models, and 2.0 V for standard types
• K6- III : 2.0 V

• K6 -IIIE : 400, 450, 500 MHz and 550 MHz
• K6- III : 400, 450, 475, 500 and 550 MHz undocumented