Intel Nehalem has Hyper-Threading + 20-40% more performance

Intel's old Hyper-Threading technology will return with the Nehalem cores in 2008.

Sources indicated that Intel acknowledges AMD's claim that the company has developed a "true" quad-core processor, while Intel is relying on a dual-die package with two dual-core processors at this time as well as 45 nm Penryn quad-core CPUs. However, the company also believes that AMD's decision to integrate the memory controller into the CPU has a downside and forces the manufacturer to compromise cache size and stick to only two memory channels.

Intels' initial answer to AMD's Barcelona quad-core will be the "Harpertown" processor for servers and "Yorkfield" for desktop PCs. Both chips will be based on a 45 nm shrink of the current Core architecture and continue to use a multi-chip-package for quad-core CPUs. Intel claims that the multi-chip package provides a flexibility that "enables Intel chip designers to put two cores in one package, which AMD can't do in such a straightforward way," sources indicated.

Nehalem will be an "evolutionary step" up from the Core architecture, with expected performance gains from 20 to 40 percent.

The Nehalem processors will have additional instruction sets and up to 12MB shared cache memory. Hyper-Threading will be rebranded to symmetric multi-threading (SMT).

Hyperthreading originally simulated a second virtual core within a physical core CPU and was the first step to take advantage of multi-threaded applications on the desktop. In the 45 nm market, this technology would simulate four additional threads in quad-core processors and eight additional threads in eight-core processors (for a total of 16), which are expected to debut in the 45 nm generation of Intel processors.