AMD Sempron Processor vs. AMD Athlon Processor

[Jalabala]

hi there

I am a bit confused with the upcoming models of processors which are indulging like anything. The query is how can we differntiate a AM?D processors, I mean that AMD Sempron and AMD Athlon. How can one judge the better of these. Please provide some view regarding this problem

[SUpER CoP]

AMD SEMPRON:

Sempron has been the marketing name used by AMD for several different entry level desktop CPUs, using several different technologies and CPU socket formats.

The Sempron replaced the AMD Duron processor and competes against Intel's Celeron D processor.

AMD coined the name from the Latin semper, which means "always", to suggest the Sempron is suitable for "daily use, practical, and part of everyday life".

[JAMES_911]

AMD Athlon Processors:

Athlon is the brand name applied to a series of different x86 processors designed and manufactured by AMD. The original Athlon (now called Athlon Classic) was the first seventh-generation x86 processor and, in a first, retained the initial performance lead it had over Intel's competing processors for a significant period of time. AMD has continued the Athlon name with the Athlon 64, an eighth-generation processor featuring x86-64 (later renamed AMD64) technology.

[Omari]

AMD Sempron Processor:

The first Sempron CPUs were based on the Athlon XP architecture using the Thoroughbred or Thorton core. These models were equipped with the Socket A interface, 256 KiB L2 cache and 166 MHz Front side bus (FSB 333). Thoroughbred cores natively had 256 KiB L2 cache, but Thortons had 512 KiB L2 cache, half of which was disabled and could sometimes be reactivated by bridge modification. Later, AMD introduced the Sempron 3000+ CPU, based on the Barton core with 512 KiB L2 cache. From a hardware and user standpoint, the Socket A Sempron CPUs were essentially identical to Athlon XP desktop CPUs with a new brand name. AMD has ceased production of all Socket A Sempron CPUs.

The second generation (Paris/Palermo core) was based on the architecture of the Socket 754 Athlon 64. Some differences from Athlon 64 processors include a reduced cache size (either 128 or 256 KiB L2), and the absence of AMD64 support in earlier models. Apart from these differences, the Socket 754 Sempron CPUs share most features with the more powerful Athlon 64, including an integrated (on-die) memory controller, the HyperTransport link, and AMD's "NX bit" feature.

In the second half of 2005, AMD added 64-bit support (AMD64) to the Sempron line. Some journalists (but not AMD) often refer to this revision of chips as "Sempron 64" to distinguish it from the previous revision. AMD's intent in releasing 64-bit entry-level processors was to extend the market for 64-bit processors, which at the time of Sempron 64's first release, was a niche market.

In 2006, AMD announced the Socket AM2 and Socket S1 line of Sempron processors. These are functionally equivalent to the previous generation, except they have a dual-channel DDR2 SDRAM memory controller which replaces the single-channel DDR SDRAM version. The TDP of the standard version remains at 62 W (watts), while the new "Energy Efficient Small Form Factor" version has a reduced 35 W TDP. The Socket AM2 version also does not require a minimum voltage of 1.1 volts to operate, whereas all socket 754 Semprons with Cool'n'Quiet did. In 2006, AMD was selling both Socket 754 and Socket AM2 Sempron CPUs concurrently. In the middle of 2007 AMD appears to have dropped the 754 line and is shipping AM2 and S1 Semprons.

[lorenz]

AMD Athlon Processor:


Internally, the Athlon is a fully seventh generation x86 processor, the first of its kind. Like the AMD K5 and K6, the Athlon is a RISC microprocessor which decodes x86 instructions into its own internal instructions at runtime. The CPU is an out-of-order design, again like previous post-5x86 AMD CPUs. The Athlon utilizes the Alpha 21264's EV6 bus architecture with double data rate (DDR) technology. This means that at 100 MHz the Athlon front side bus actually transfers at a rate similar to a 200 MHz single data rate bus (referred to as 200 MT/s), which was superior to the method used on Intel's Pentium III (with SDR bus speeds of 100 MHz and 133 MHz).

AMD designed the CPU with more robust x86 instruction decoding capabilities than that of K6, to enhance its ability to keep more data in-flight at once. Athlon's CISC to RISC decoder triplet could potentially decode six x86 operations per clock, although this was somewhat unlikely in real-world use. The critical branch predictor unit, essential to keeping the pipeline busy, was enhanced compared to what was onboard the K6. Deeper pipelining with more stages allowed higher clock speeds to be attained.[4] Whereas the AMD K6-III+ topped out at 570 MHz due to its short pipeline, even when built on the 180 nm process, the Athlon was capable of going much higher.

AMD ended its long-time handicap with floating point x87 performance by designing a super-pipelined, out-of-order, triple-issue floating point unit. Each of its 3 units were tailored to be able to calculate an optimal type of instructions with some redundancy. By having separate units, it was possible to operate on more than one floating point instruction at once. This FPU was a huge step forward for AMD. While the K6 FPU had looked anemic compared to the Intel P6 FPU, with Athlon this was no longer the case.

The 3DNow! floating point SIMD technology, again present, received some revisions and a name change to "Enhanced 3DNow!". Additions included DSP instructions and an implementation of the extended MMX subset of Intel SSE.

The Athlon's CPU cache consisted of the typical two levels. Athlon was the first x86 processor with a 128 KB[7] split level 1 cache; a 2-way associative, later 16-way, cache separated into 2×64 KB for data and instructions (Harvard architecture). This cache was double the size of K6's already large 2×32 KB cache, and quadruple the size of Pentium II and III's 2×16 KB L1 cache. The initial Athlon (Slot A, later renamed Athlon Classic) used 512 KB of level 2 cache separate from the CPU, on the processor cartridge board, running at 50% to 33% of core speed. This was done because the 250 nm manufacturing processes was too large to allow for on-die cache while maintaining cost-effective die size. Later Athlon CPUs, afforded greater transistor budgets by smaller 180 nm and 130 nm process nodes, moved to on-die L2 cache at full CPU clock speed.