Hardware Reference
In-Depth Information
AMD Sempron
AMD introduced the Sempron line of processors in 2004 as a replacement for the Duron
brand, and to provide an economy line of processors designed to compete with the Intel
Celeron D. Just as the Intel Celeron name long ago ceased to identify a particular pro-
cessor and instead is a brand that identifies various types of low-cost, reduced-perform-
ance processors, AMD's Sempron brand follows a similar course. Sempron identifies
Socket A processors based on the Athlon XP as well as Socket 754, 939, AM2, and AM3
processors based on the Athlon 64 and 64 X2.
TheSocketAversionoftheAMDSempronisbasedontheAthlonXPprocessor,whereas
the Socket 754, 939, AM2, and AM3 versions are based on the Athlon 64. Sempron X2
models are dual-core processors based on the Athlon X2. The difference is that the Sem-
pron versions are offered in lower processor and bus clock speeds, with smaller caches
and sometimes limited features to justify a lower price point.
Because AMD has offered Sempron processors in many distinctive variations, it's easy
to get confused as to which is which and what features are included in a specific model.
By looking up the processor on the AMD Desktop Processor Comparison website (
ht-
tp://products.amd.com/enus/DesktopCPUResult.aspx
)
, you can find out the exact spe-
cification,includingsockettype,voltage,revision,cachesize,andotherinformationabout
the chip. You can also use software tools such as CPU-Z (
www.cpuid.com
)
to find more
detailed information about a given processor.
AMD Athlon X2, 64 X2, and 64 FX
The 64-bit Athlon 64 processors were designed with multicore updates in mind from the
beginning. The desktop Athlon 64 X2 was introduced in May 2005. The Athlon 64 X2
uses several core designs, with different options and features.
The following are major features of the Athlon 64 X2:
• 65nm or 90nm manufacturing process
• Actual clock speeds of 1.9GHz-3.0GHz
• Socket 939, AM2, and 1207FX form factors
• 1GHz HyperTransport interconnect (4GBps bandwidth)
The design of these processors has always included room for the second processor core
along with a crossbar memory controller to enable the processor cores to directly com-
municate with each other without using the North Bridge, as with Intel's initial dual-core
processors.
Figure 3.38
illustrates the internal design of the Athlon 64 X2.
Figure 3.38
The Athlon 64 X2 uses the integrated crossbar memory controller present from the beginning
of the Athlon 64 processor design to enable the processor cores to communicate with each other.
