More than likely, you have seen the stickers on the front of computers
saying "Intel Inside." As you might guess, this computer has an Intel processor.
This sticker and the associated aide campaign is important for name recognition.
For many people, the name Intel has become synonymous with CPUs for PCs.
Many people may have heard the name of other CPU
vendors, but often feel
they are simply cheap "clones." This is unfortunate, because the performance of
these CPUs is comparable to the Intel CPUs. Although these other vendors
generally release chips with the same performance several months after the
comparable one from Intel, they are typically less expensive and therefore have
a better price-performance ratio.
This is where business buyers really look. If a product provides the
necessary performance and reliability at a lower price, it does not make
business sense to pay for something just because it has an expensive television
add. Therefore, more and more business, including PC manufacturers are switching
to AMD CPUs.
One of the first successful "clones" of the Intel CPUs was the AMD AM5x86.
The first assumption is that the "5" in that its name indicates that it is a
clone of the Intel Pentium. Instead, it is much better to think of the AM5x86 at
a high-end version of the 486. Tests have shown that a 133Mhz AM5x86 will not
quite outperformed a 90MHz Pentium, but will outperform one at 70 MHz. Because
of the reduced cost, you still get better performance dollar for dollar, despite
the 48 faster processor.
The AMD K5 was the first Pentium-class CPU
developed by AMD. One interesting
aspect of the case five, is that it "translates" the Intel instructions into
fixed length RISC instructions. This makes executing the instructions a lot
faster, because the CPU
does not need to waste time figuring out how on the
instruction really is. In addition, since all instructions are the same length,
they can be loaded more efficiently into the K5's six-stage instructions
pipeline, which can process for instruction simultaneously.
Following the K5, AMD logically came out with the K6. One benefit of this
CPU was the fact that and was the first on market which used Intel's own MMX
technology. In addition, the K6 has instruction pipelines which are fed by a set
of four instruction decoders. Like the K5, the K6 translates the Intel
instructions into RISC instructions before executing them. Added to that the K6
has separate instruction and data caches like the Pentium, but those in the K6
or four times as large (32KB).
The successor to the successful AMD-K6 series is the AMD-K6-2, which is the
to offers AMD's 3DNow! Technology. As you might guess from its name
implies, 3DNow! improves system performance when displaying 3D graphics,
something Intel's MMX technology was not designed to do. However, MMX does
provide some performance improvements, so the AMDK6-2 includes MMX, as well. As
of this writing, the AMD-K6-2 is available in speeds from 300MHz to 475MHz.
Next came the AMD-K6-III series. As with the AMD-K6-2, the AMD-K6-III series
also provides AMD's 3DNow! technology. One of the most significant improvements
is the addition of an addition CPU,
which give it a "tri-level" cache.
providing a maximum cache
of 2.3MB, which is more than four times as much as
possible with the Intel Pentium III Processors. In addition, the L2 cache
operates at the same speed as the CPU.
This means the 450MHz version has the
potential to outperform a 500MHz Pentium III.
The next step is the AMD-K7 processor. As of this writing, it has not yet
been released, but the features announced by AMD are exciting. One important
aspect is that it is expected to be the first CPU
to support a 200 MHz system
bus. This includes a nine stage, superscalar execution pipeline, with a 128KB L1
cache. This is twice what is currently available.