15
CPU Technical Background
The CPU socket on your KTAPRO motherboard is known as Socket A. This name was
given to it by AMD, it supports both the Duron™ and the AMD Athlon™ processors.
Athlon CPU
There are several types of Athlon CPUs, Model 1, 2 and 4. The principal difference
between the earlier Athlon Model 1 and Model 2 processors and the model 4 is the use of
256kB on-die cache, rather than 512kB of off-die cache. This allows the cache to run at the
clockspeed of the processor, rather than at a fraction (1/3, 2/5, 1/2) as in the earlier Athlons.
This constraint is the principal performance limit for the higher speed Athlon Model 2
processors. The use of on-die cache also allows the CPU to use a 0.05V lower core voltage
and a corresponding reduction in power consumption of approximately 10-20%. This
reduces the temperature of the processor.
There are two model 4 socket A CPUs, one using copper interconnects and the other
aluminium. The former is coloured blue and the latter green. The copper-based Athlon
CPUs run cooler than the aluminium versions.
Duron CPU
The Duron is AMDs low cost processor. It is very similar to the Athlon, using the same
Socket A interface. The principal difference between the Athlon and the Duron is in the
amount of full speed on-die L2 cache (64k rather than 256k) and a core voltage of 1.5v
rather than 1.7v to 1.8v, meaning a lower power consumption of just 22W. According to
tests it runs at about 90% of the performance of an Athlon of the same clock frequency and
at about 92-99% of the performance of an Athlon Model 1 or 2 of the same clock frequency.
It easily beats the same clock speed Intel Celeron processor and often out-classes even the
Pentium-III of the same specification.
The following gives a technical summary of the main CPU features:
System Bus:
The processor system bus is the first x86 platform bus running at or above
200MHz. At present, AMD Athlon processors are available with 266MHz and 200MHz
system buses. As one of the fastest x86 processor buses currently available, the design
delivers as high as 100 percent more peak bandwidth than any x86 system bus.
Floating Point Engine:
The AMD Athlon processor includes the first fully pipelined,
superscalar floating point engine for x86 platforms. The resulting floating point capability
is the most powerful ever delivered in an x86 processor.
Enhanced 3DNow!™ Technology:
The first x86 instruction set to use superscalar SIMD
floating point techniques. Enhanced 3DNow! technology adds 24 instructions-19 to
improve MMX integer math calculations and enhance data movement for Internet
streaming applications and 5 DSP extensions for soft modem, soft ADSL, Dolby Digital,
and MP3 applications.
