The 90 nm Smithfield contains a single die, with two adjoined but functionally separate CPU cores cut from the same wafer.

The later 65 nm Presler utilized a multi-chip module package, where two discrete dies each containing a single core reside on the CPU substrate.

[4] The final shipment date of the dual die Presler chips was August 8, 2008,[7] which marked the end of the Pentium D brand and also the NetBurst microarchitecture.

Single-threaded applications, including most older games, do not benefit much from a second core compared to an equally clocked single-core CPU.

[citation needed] However, in multitasking environments such as BSD, Linux, Microsoft Windows operating systems, other processes are often running at the same time; if they require significant CPU time, each core of the Pentium D branded processor can handle different programs, improving overall processing speed over its single-core Pentium 4 counterpart.

As a response, Intel developed Smithfield, the first x86 dual-core processor intended for desktop computers, beating AMD's Athlon 64 X2 by a few weeks.

Intel first launched Smithfield on April 16, 2005 in the form of the 3.2 GHz Hyper-threading enabled Pentium Extreme Edition 840.

On May 26, 2005, Intel launched the mainstream Pentium D branded processor lineup with initial clock speeds of 2.8, 3.0, and 3.2 GHz with model numbers of 820, 830, and 840 respectively.

Running it at over 4 GHz was possible with water cooling, and at this speed the 805 outperformed the top-of-the-line processors (May 2006) from both major CPU manufacturers (the AMD Athlon 64 FX-60 and Intel Pentium Extreme Edition 965) in many benchmarks including power consumption.

The Pentium D 820 did not work with the nForce 4 SLI Intel Edition chipset due to some power design issues, though they were rectified in the X16 version.

A week after its launch, Intel officially denied a report[9] in Computerworld Today Australia that the Pentium D branded CPUs included "secret" digital rights management features in their hardware that could be utilized by Microsoft Windows and other operating systems, but was not publicly disclosed.

In a single-processor scenario, the CPU-to-northbridge link is point-to-point and the only real requirement is that it is fast enough to keep the CPU fed with data from memory.

Leaving aside advanced issues such as cache coherency, each core can only use half of the 800 MT/s FSB bandwidth when under heavy load.

The competing AMD Athlon 64 X2, although running at lower clock rates and lacking hyper-threading, had some significant advantages over the Pentium D, such as an integrated memory controller, a high-speed HyperTransport bus, a shorter pipeline (12 stages compared to the Pentium D's 31), and better floating point performance,[11] more than offsetting the difference in raw clock speed.

Indeed, shortly after the launch of the mainstream Pentium D branded processors (26 May 2005) and the Athlon 64 X2 (31 May 2005), a consensus arose that AMD's implementation of multi-core was superior to that of the Pentium D.[12][13] As a result of this and other factors, AMD surpassed Intel in desktop PC sales at US retail stores for a period of time, although Intel retained overall market leadership because of its exclusive relationships with direct sellers such as Dell.