Editing Pentium 4 (section)

===Prescott===
[[File:Pentium 4 Prescott 2.40GHz(1).jpg|thumb|Pentium 4 2.40A{{snd}} Prescott]]
[[File:Intel Pentium4 640 Prescott (98% Quality JPG).jpg|thumb|Intel Pentium 4 640 die shot]]
On February 1, 2004, Intel introduced a new core codenamed Prescott. The core used the [[90 nm process]] for the first time, which one analyst described as "a major reworking of the Pentium 4's microarchitecture."<ref>{{cite web |url=http://techreport.com/articles.x/6213/1 |title=Intel's Pentium 4 Prescott processor |publisher=The Tech Report |date=February 2, 2004 |access-date=2007-08-28}}</ref> Despite this overhaul, the performance gains were inconsistent. Some programs benefited from Prescott's doubled cache and SSE3 instructions, whereas others were harmed by its longer pipeline. The Prescott's microarchitecture allowed slightly higher clock speeds, but not nearly as high as Intel had anticipated. The fastest mass-produced Prescott-based Pentium 4s were clocked at 3.8&nbsp;GHz. While Northwood ultimately achieved clock speeds 70% higher than Willamette, Prescott only scaled 12% beyond Northwood. Prescott's inability to achieve greater clock speeds was attributed to the very high power consumption and heat output of the processor. This led to the processor receiving the nickname "PresHot" on forums.<ref>{{citation|url=https://hardforum.com/threads/pentium-4-prescott-3ghz-w-1mb-l2-cache-question.738873/ |title=Pentium 4 Prescott 3GHz w/1MB L2 cache question |publisher=HardForum |date=2004-03-07 |access-date=2020-04-23}}</ref> In fact, Prescott's power and heat characteristics were only slightly higher than those of Northwood of the same speed and nearly equal to the Gallatin-based Extreme Editions, but since those processors had already been operating near the limits of what was considered thermally acceptable, this still posed a major issue.<ref>{{citation|url=http://www.anandtech.com/show/1296/3 |title=CPU Heat Comparison: How Hot is Prescott? |publisher=AnandTech |date=2004-04-16 |access-date=2012-01-08}}</ref>

The release of Prescott also coincided with the launch of [[LGA 775]] and the [[BTX (form factor)|BTX form factor]], which were also criticized. Tests showed that a given Pentium 4 made for LGA 775 consumed more power and produced more heat than the exact same chip in a socket 478 package. The BTX form factor, meanwhile, showed signs of having been designed for the sole purpose of managing the Prescott's heat output at the expense of other components and concerns, such as blowing hot air from the CPU directly into the graphics card's heatsink/fan. These magnified the perception of Prescott as an excessively hot chip.

The Prescott Pentium 4 contains 125 million transistors and has a die area of 112&nbsp;mm<sup>2</sup>.<ref>{{citation|url=http://ark.intel.com/products/27505/Intel-Pentium-4-Processor-supporting-HT-Technology-3_40E-GHz-1M-Cache-800-MHz-FSB |title=Intel Pentium 4 Processor supporting HT Technology 3.40E GHz |publisher=ARK.Intel.com |date=2004-02-02 |access-date=2012-12-15}}</ref><ref name="MPR-2004-02-02">Glaskowsky, Peter N. (2 February 2004). "Prescott Pushes Pipelining Limits". ''[[Microprocessor Report]]''.</ref> It was fabricated in a 90&nbsp;nm process with seven levels of [[copper interconnect]].<ref name="MPR-2004-02-02"/> The process has features such as [[strained silicon]] transistors and [[low-κ dielectric|low-κ]] carbon-doped silicon oxide (CDO) dielectric, which is also known as organosilicate glass (OSG).<ref name="MPR-2004-02-02"/> The Prescott was first fabricated at the D1C development [[Fab (semiconductors)|fab]] and was later moved to F11X production fab.<ref name="MPR-2004-02-02"/>

Originally, Intel released two Prescott lines on Socket 478: the E-series, with an 800&nbsp;MT/s FSB and [[Hyper-Threading]] support, and the low-end A-series, with a 533&nbsp;MT/s FSB and Hyper-Threading disabled. LGA 775 Prescott CPUs use a rating system, labeling them as the 5xx series (Celeron Ds are the 3xx series, while Pentium Ms are the 7xx series). The LGA 775 version of the E-series uses model numbers 5x0 (520–560), and the LGA 775 version of the A-series uses model numbers 5x5 and 5x9 (505–519). The fastest, the 570J and 571, is clocked at 3.8&nbsp;GHz. Plans to mass-produce a 4&nbsp;GHz Pentium 4 were cancelled by Intel in favor of dual core processors, although some European retailers claimed to be selling a Pentium 4 580, clocked at 4&nbsp;GHz. The E-series Prescott, as well as the low-end 517 and 524, incorporates Hyper-Threading in order to speed up some processes that use multithreaded software, such as video editing.

The Prescott microarchitecture was designed to support Intel 64, Intel's implementation of the AMD-developed [[x86-64]] 64-bit extensions to the x86 architecture, but the initial models shipped with their 64-bit capability disabled. Intel stated that it did not intend to release 64-bit CPUs in retail channels, instead releasing the 64-bit capable F-series to OEMs only.<ref name=prescott-no-64bit>{{cite web |url=http://www.xbitlabs.com/news/cpu/display/20040325151223.html |title=Intel Says No to 64-bit Pentium 4 in Retail |website=XBitLabs |access-date=2022-05-08 |url-status=dead |archive-url=https://web.archive.org/web/20040603014127/http://www.xbitlabs.com/news/cpu/display/20040325151223.html |archive-date=2004-06-03}}</ref> However, they were later made available to the general public as the 5x1 series. A number of low-end Intel 64-enabled Prescotts, with 533&nbsp;MHz FSB speed, were also released.

The E0 stepping of the Prescott series introduced the [[XD bit]] feature.<ref>{{citation|url=http://www.intel.com/business/bss/infrastructure/security/xdbit.htm |title=IT Infrastructure – Intel Resources for IT Managers |publisher=Intel.com |access-date=2012-01-08}}</ref> This technology, introduced to the x86 architecture by AMD as [[NX bit|NX (No eXecute)]], can help prevent certain types of malicious code from [[Exploit (computer security)|exploiting]] a [[buffer overflow]] to get executed. Models supporting XD bit include the 5x0J and 5x1 series as well as the low-end 5x5J and 5x6.

The Prescott processors are the first to support [[SSE3]], along with all [[Pentium D]] processors.

====Prescott 2M (Extreme Edition)====
Intel, by the first quarter of 2005, released a new Prescott core with 6x0 numbering, codenamed Prescott 2M. It is also sometimes known by the name of its [[Xeon]] derivative, Irwindale.<ref name="anand-irwindale">{{cite web|url=https://www.anandtech.com/show/1524 |website=AnandTech |date=2005-02-21 |access-date=2022-05-08 |title=Intel CPU Roadmap Update}}</ref> It features Hyper-Threading, [[Intel 64]], the XD&nbsp;bit, [[SpeedStep|EIST]] (Enhanced Intel SpeedStep Technology), [[Thermal Monitor 2]] (for processors at 3.6&nbsp;GHz and above), and 2&nbsp;MB of L2 cache. However, AnandTech found that this resulted in 17% higher cache latency compared to Prescott, which combined with the lack of consumer-targeted programs requiring more cache, largely negated the advantage that added cache introduced.<ref name="anand-cache">{{cite web|url=https://www.anandtech.com/show/1621/2 |website=AnandTech |date=2004-10-27 |access-date=2022-05-08 |title=Twice the Cache - 17% Higher Latency }}</ref> Rather than being a targeted speed boost the double size cache was intended to provide the same space and hence performance for [[Long_mode|64-bit mode]] operations, due to the doubled [[Word_(computer_architecture)#Table_of_word_sizes|word size]] compared to 32-bit mode.

On November 14, 2005, Intel released Prescott 2M processors with VT ([[Hardware-assisted virtualization|Virtualization]] Technology, codenamed Vanderpool) enabled. Intel only released two models of this Prescott 2M category: 662 and 672, running at 3.6&nbsp;GHz and 3.8&nbsp;GHz, respectively.<ref>{{cite web|url=https://ark.intel.com/content/www/us/en/ark/products/27486/intel-pentium-4-processor-662-supporting-ht-technology-2m-cache-3-60-ghz-800-mhz-fsb.html|title=Intel Pentium 4 Processor 662 supporting HT Technology (2M Cache, 3.60 GHz, 800 MHz FSB)|website=Product Specifications|publisher=[[Intel]]}}</ref><ref>{{cite web|url=https://ark.intel.com/content/www/us/en/ark/products/27488/intel-pentium-4-processor-672-supporting-ht-technology-2m-cache-3-80-ghz-800-mhz-fsb.html|title=Intel Pentium 4 Processor 672 supporting HT Technology (2M Cache, 3.80 GHz, 800 MHz FSB)|website=Product Specifications|publisher=[[Intel]]}}</ref><ref>https://www.cpu-world.com/CPUs/Pentium_4/Intel-Pentium%204%20662%203.6%20GHz%20-%20HH80547PG1042MH.html</ref><ref>https://www.cpu-world.com/CPUs/Pentium_4/Intel-Pentium%204%20672%203.8%20GHz%20-%20HH80547PG1122MH.html</ref>