Processor Types and Specifications - Upgrading and Repairing PCs - page 109

Processors with power levels below 35W are also available but not listed here. See
http://ark.intel.com and search for “Ivy Bridge” to see lower-powered processors in this family.
Pentium processors in the G2100 series also use the Ivy Bridge microarchitecture but feature smaller
cache sizes and have only two cores without HTT, compared to Core i3's four cores with HTT.
Intel Atom
Intel introduced its Atom ultra low power processors in 2008 and refreshed the line with new models
with integrated graphics (D25xx series) in 2012. Although a few vendors have created very low-end
desktop computers using Atom, this processor is designed primarily for netbooks, tablets, home
servers, and other specialized uses. It is a 64-bit processor fully compatible with x86 and 64-bit
versions of Windows and other operating systems, and some models support HT Technology.
However, it supports only SSSE3 instructions, has a 4GB memory limit, and includes only two cores.
To learn more about Atom, see http://ark.intel.com .
AMD K6 Processors
How did AMD begin to design and produce P6-type processors in its own facilities (fabs)? It's an
interesting story that began with a company called NexGen and its Pentium rival, the Nx586. After
using NexGen technology for its first P6-class processors, AMD later designed and fabricated the
Athlon and Duron processors, which were true sixth-generation designs using their own proprietary
connections to the system.
NexGen Nx586
NexGen was founded by Thampy Thomas, who hired some of the people formerly involved with the
486 and Pentium processors at Intel. At NexGen, developers created the Nx586, a processor that was
functionally the same as the Pentium but not pin compatible. As such, it was always supplied with a
motherboard; in fact, it was usually soldered in. NexGen did not manufacture the chips or the
motherboards they came in; for that it hired IBM Microelectronics. Later NexGen was bought by
AMD, right before it was ready to introduce the Nx686—a greatly improved design by Greg Favor
and a true competitor for the Pentium. AMD took the Nx686 design and combined it with a Pentium
electrical interface to create a drop-in Pentium-compatible chip called the K6, which actually
outperformed the original from Intel.
The Nx586 had all the standard fifth-generation processor features, such as superscalar execution
with two internal pipelines and a high-performance integral L1 cache with separate code and data
caches. One advantage is that the Nx586 includes separate 16KB instruction and 16KB data caches,
compared to 8KB each for the Pentium. These caches keep key instructions and data close to the
processing engines to increase overall system performance.
The Nx586 also includes branch prediction capabilities, which are one of the hallmarks of a sixth-
generation processor. Branch prediction means the processor has internal functions to predict
program flow to optimize the instruction execution.
The Nx586 processor also featured a RISC core. A translation unit dynamically translates x86