Editing Pentium 4 (section)

===Northwood (Extreme Edition)===
In September 2003, at the Intel Developer Forum, the Pentium 4 Extreme Edition (P4EE) was announced, just over a week before the launch of [[Athlon 64]] and [[Athlon 64 FX]]. The design was mostly identical to Pentium 4 (to the extent that it would run in the same motherboards), but differed by an added 2&nbsp;MB of level 3 cache. It shared the same Gallatin core as the Xeon MP, though in a Socket 478 form factor (as opposed to Socket 603 for the Xeon MP) and with an 800&nbsp;MT/s bus, twice as fast as that of the Xeon MP.
[[File:XtremeEdition.jpg|thumb|The 1st Extreme Edition Demoed Computer]]

While Intel maintained that the Extreme Edition was aimed at gamers, critics viewed it as an attempt to steal the Athlon 64's launch thunder, nicknaming it the "Emergency Edition".<ref>{{Cite news|url=https://www.extremetech.com/computing/55632-review-intel-prescott-pentium-4-processor/7?print|title=Review: Intel Prescott Pentium 4 Processor - Page 7 of 15 - ExtremeTech|newspaper=Extremetech |date=30 January 2004 |last1=Case |first1=Loyd }}</ref> With a price tag of $1000, it was also referred to as the "Expensive Edition" and "Extremely Expensive".<ref>{{Cite web|url=https://www.theregister.com/2003/10/31/intel_pentium_4_extremely_expensive/|title=Intel Pentium 4 Extremely Expensive Edition to ship Monday|first=Tony|last=Smith|website=www.theregister.com}}</ref>

The added cache generally resulted in a noticeable performance increase in most processor intensive applications. Multimedia encoding and certain games benefited the most, with the Extreme Edition outperforming the Pentium 4, and even the two Athlon 64 variants, although the lower price and more balanced performance of the Athlon 64 (particularly the non-FX version) led to it usually being seen as the better value proposition. Nonetheless, the Extreme Edition did achieve Intel's apparent aim, which was to prevent AMD from being the performance champion with the new Athlon 64, which was winning every single major benchmark over the existing Pentium 4s.

In January 2004, a 3.4&nbsp;GHz version was released for Socket 478, and in Summer 2004 the CPU was released using the new Socket 775 ([[LGA 775]]). A slight performance increase was achieved in late 2004 by increasing the bus speed from 800&nbsp;MT/s to 1066&nbsp;MT/s, resulting in a 3.46&nbsp;GHz Pentium 4 Extreme Edition. By most metrics, this was on a per-clock basis the fastest single-core NetBurst processor that was ever produced, even outperforming many of its successor chips (not counting the dual-core Pentium D). Afterwards, the Pentium 4 Extreme Edition was migrated to the Prescott core. The new 3.73&nbsp;GHz Extreme Edition had the same features as a 6x0-sequence Prescott 2M, but with a 1066&nbsp;MT/s bus. In practice however, the 3.73&nbsp;GHz Pentium 4 Extreme Edition almost always proved to be slower than the 3.46&nbsp;GHz Pentium 4 Extreme Edition, which is most likely due to the lack of an L3 cache and the longer instruction pipeline. The only advantage the 3.73&nbsp;GHz Pentium 4 Extreme Edition had over the 3.46&nbsp;GHz Pentium 4 Extreme Edition was the ability to run 64-bit applications since all Gallatin-based Pentium 4 Extreme Edition processors lacked the Intel 64 (then known as EM64T) instruction set.

Although never a particularly good seller, especially since it was released in a time when AMD was asserting near total dominance in the processor performance race, the Pentium 4 Extreme Edition established a new position within Intel's product line, that of an enthusiast oriented chip with the highest-end specifications offered by Intel chips, along with unlocked multipliers to allow for easier overclocking. In this role it has since been succeeded by the [[Pentium D#Pentium D/Extreme Edition|Pentium Extreme Edition]] (The Extreme version of the dual-core [[Pentium D]]), the [[Intel Core 2#Duo, Quad, and Extreme|Core 2 Extreme]], the [[List of Intel Core i7 processors|Core i7]] and the [[List of Intel Core i9 processors|Core i9]].

Contrary to popular belief, however, the Socket 478 versions of the Pentium 4 Extreme Edition CPUs such as the Gallatin-based Pentium 4 Extreme Edition for Socket 478 all have a locked multiplier, meaning that they are not overclockable unless the [[front-side bus]] speeds are increased (which runs the potential risks of erratic behaviors such as reliability and stability issues). Only the Socket 775/LGA 775 versions of the Pentium 4 Extreme Edition, as well as the Pentium Extreme Edition (Smithfield) and Engineering Sample CPUs have unlocked multipliers.