Editing Pentium III (section)

==={{Anchor|Coppermine}}Coppermine===
[[File:KL Intel Pentium III Coppermine.jpg|thumb|right|A 900 MHz ''Coppermine'' FC-PGA Pentium III.]]
[[File:Intel@180nm@P6@Coppermine@Pentium III@unknow Slot1 DSCx1 polysilicon microscope stitched@5x (38025178422).jpg|thumb|Coppermine Die shot]]
The second version, codenamed Coppermine (Intel product code: 80526), was released on October 25, 1999 running at 500, 533, 550, 600, 650, 667, 700, and 733&nbsp;MHz. From December 1999 to May 2000, Intel released Pentium IIIs running at speeds of 750, 800, 850, 866, 900, 933 and 1000&nbsp;MHz (1&nbsp;GHz). Both 100&nbsp;MT/s FSB and 133&nbsp;MT/s FSB models were made. For models that were already available with the same frequency, an "E" was appended to the model name to indicate cores using the new 180&nbsp;nm fabrication process. An additional "B" was later appended to designate 133&nbsp;MHz FSB models, resulting in an "EB" suffix. In overall performance, Coppermine had a small advantage over the [[Advanced Micro Devices]] (AMD) [[Athlon]]s it was released against, which was reversed when AMD applied their own die shrink and added an on-die L2 cache to the Athlon. Athlon held the advantage in floating-point intensive code, while the Coppermine could perform better when SSE optimizations were used, but in practical terms there was little difference in how the two chips performed, clock-for-clock. However, AMD were able to clock the Athlon higher, reaching speeds of 1.2&nbsp;GHz before the launch of the Pentium 4.

In performance, Coppermine arguably marked a bigger step than Katmai by introducing an on-chip L2 cache, which Intel names ''Advanced Transfer Cache'' (ATC). The ATC operates at the core clock rate and has a capacity of 256&nbsp;KB, twice that of the on-chip cache formerly on Mendocino Celerons. It is eight-way [[set-associative]] and is accessed via a ''Double Quad Word Wide'' 256-bit bus, four times as wide as Katmai's. Further, latency was dropped to a quarter compared to Katmai. Another marketing term by Intel was ''Advanced System Buffering'', which encompassed improvements to better take advantage of a 133&nbsp;MT/s system bus. These include 6 fill buffers (vs. 4 on Katmai), 8 bus queue entries (vs. 4 on Katmai) and 4 write-back buffers (vs. 1 on Katmai).<ref name="ENHANCEMENTS">{{cite web|url=http://www.tomshardware.com/reviews/intel,138-3.html|author=Pabst, Thomas|date=October 25, 1999|title=Coppermine's New Enhancements|access-date=September 1, 2017}}</ref> Under competitive pressure from the [[AMD]] [[Athlon]], Intel reworked the internals, finally removing some well-known [[Pipeline (computing)|pipeline]] stalls.{{citation needed|date=September 2017}} As a result, applications affected by the stalls ran faster on Coppermine by up to 30%.{{citation needed|date=September 2017}} The Coppermine contained 29 million transistors and was fabricated in a 180&nbsp;nm process.

The Coppermine was available in 370-pin FC-PGA or FC-PGA2 for use with [[Socket 370]], or in SECC2 for Slot 1 (all speeds except 900 and 1100). FC-PGA and Slot 1 Coppermine CPUs have an exposed die, however most higher frequency SKUs starting with the 866&nbsp;MHz model were also produced in FC-PGA2 variants that feature an [[integrated heat spreader]] (IHS). This in itself did not improve thermal conductivity, since it added another layer of metal and [[thermal paste]] between the die and the heatsink, but it greatly assisted in holding the heatsink flat against the die. Earlier Coppermines without the IHS made heatsink mounting challenging.<ref>{{cite web |url=http://www.thetechzone.com/reviews/cooler/alpha/coppermine_coolers/ |title=Alpha FC-PAL35T & POP66T Cooler Review |website=The Tech Zone |date=April 12, 2000 |url-status=dead |archive-url=https://web.archive.org/web/20060627003431/http://www.thetechzone.com/reviews/cooler/alpha/coppermine_coolers/ |archive-date=June 27, 2006}}</ref> If the heatsink was not situated flat against the die, heat transfer efficiency was greatly reduced. Some heatsink manufacturers began providing pads on their products, similar to what AMD did with the "Thunderbird" Athlon to ensure that the heatsink was mounted flatly. The enthusiast community went so far as to create shims to assist in maintaining a flat interface.<ref>{{Cite web |last=Verbist |first=Tim |date=December 3, 2000 |url=http://www.overclockersonline.com/index.php?page=articles&num=31 |title=Copper Shims |website=Overclockers Online}}</ref>

A 1.13&nbsp;GHz version (S-Spec SL4HH) was released in mid-2000 but famously recalled after a collaboration between [[HardOCP]] and [[Tom's Hardware]]<ref name="Problems">{{cite web |last=Pabst |first=Thomas |date=August 28, 2000 |title=Intel Admits Problems With Pentium III 1.13 GHz: Production and Shipments Halted |url=http://www.tomshardware.com/reviews/intel-admits-problems-pentium-iii-1,235.html |website=Tom's Hardware}}</ref> discovered various instabilities with the operation of the new CPU speed grade. The Coppermine core was unable to reliably reach the 1.13&nbsp;GHz speed without various tweaks to the processor's microcode, effective cooling, higher voltage (1.75 V vs. 1.65 V), and specifically validated platforms.<ref name="Problems"/> Intel only officially supported the processor on its own VC820 [[List of Intel chipsets|i820]]-based motherboard, but even this motherboard displayed instability in the independent tests of the hardware review sites. In benchmarks that were stable, performance was shown to be sub-par, with the 1.13&nbsp;GHz CPU equalling a 1.0&nbsp;GHz model. Tom's Hardware attributed this performance deficit to relaxed tuning of the CPU and motherboard to improve stability.<ref>{{cite web|last=Pabst|first=Thomas|url=http://www.tomshardware.com/reviews/latest-update-intel,236-2.html|title=Latest Update On Intel's 1.13 GHz Pentium III|website=Tom's Hardware|date=August 28, 2000}}</ref> Intel needed at least six months to resolve the problems using a new cD0 stepping and re-released 1.1&nbsp;GHz and 1.13&nbsp;GHz versions in 2001.

Microsoft's [[Xbox (console)|Xbox]] game console uses a variant of the Pentium III/Mobile Celeron family in a [[Micro-PGA2]] form factor. The sSpec designator of the chips is SL5Sx, which makes it more similar to the Mobile Celeron [[List of Intel Celeron processors#"Coppermine-128" (180 nm)|Coppermine-128]] processor. It shares with the Coppermine-128 Celeron its 128&nbsp;KB L2 cache, and 180&nbsp;nm process technology, but keeps the 8-way cache associativity from the Pentium III.<ref>{{cite web|url=http://www.vanshardware.com/articles/2001/december/011206_More_On_Xbox_CPU/011206_More_On_Xbox_CPU.htm|title=VHJ: More on the Xbox CPU|website=Van's Hardware Journal}}</ref>

Although its codename could give the impression that it used [[copper interconnects]], in reality, its interconnects were aluminium.