View source for Power Mac G5

{{short description|Line of tower computers designed and manufactured by Apple}}
{{Use mdy dates|date=December 2014}}

{{Distinguish|iMac G5|Power Mac G4|iMac G4|Power Mac G4 Cube|PowerBook G4|iBook G4}}
{{Infobox information appliance
| name = Power Mac G5
| developer = [[Apple Inc.|Apple Computer, Inc.]]
| type = [[Desktop computer|Desktop]]
| photo = [[File:Apple Power Macintosh G5 Late 2005 02.jpg|200px]]
| caption = Apple Power Mac G5
| first_release_date = June 23, 2003
| discontinuation_date = August 7, 2006
| processor = 1.6 – 2.7 GHz [[PowerPC 970|PowerPC G5]]<br />Single-processor<br />Dual-processors, single-core<br />Dual-core<br />Dual-processors, dual-core
| baseprice = {{USD|1999|2003|round=-1}}
| predecessor = [[Power Mac G4]]
| successor = [[Mac Pro]]
| logo = [[File:Power Mac G5.svg|frameless|class=skin-invert]]
| related = {{Flatlist|
*[[iMac G5]]
*[[PowerBook G4]]
}}
| family = [[Power Macintosh]]
}}

The '''Power Mac G5''' is a series of [[personal computer]]s designed, manufactured, and sold by [[Apple Inc.|Apple Computer, Inc.]] from 2003 to 2006 as part of the [[Power Macintosh|Power Mac]] series.  When introduced, it was the most powerful computer in Apple's [[Mac (computer)|Macintosh]] lineup, and was marketed by the company as the world's first 64-bit desktop computer.<ref>{{cite web | url = https://www.apple.com/ca/newsroom/2003/06/23Apple-Unleashes-the-Worlds-Fastest-Personal-Computer-the-Power-Mac-G5/ | title = Apple Unleashes the World's Fastest Personal Computer—the Power Mac G5 | publisher = Apple | access-date = September 7, 2017 | archive-date = September 7, 2017 | archive-url = https://web.archive.org/web/20170907080441/https://www.apple.com/ca/newsroom/2003/06/23Apple-Unleashes-the-Worlds-Fastest-Personal-Computer-the-Power-Mac-G5/ | url-status = live }}</ref>  It was also the first desktop computer from Apple to use an [[Anodizing|anodized]] [[aluminum]] alloy enclosure, and one of only three computers in Apple's lineup to utilize the [[PowerPC 970]] CPU, the others being the [[iMac G5]] and the [[Xserve#Xserve G5|Xserve G5]].

Three generations of Power Mac G5 were released before it was discontinued as part of the [[Mac transition to Intel processors]], making way for its replacement, the [[Mac Pro]]. The Mac Pro retained a variation of the G5's enclosure design for seven more years, making it among the longest-lived designs in Apple's history.<ref>{{cite web | url = https://www.macworld.com/article/2042702/ten-years-in-the-shadow-of-the-power-mac-g5.html | title = Ten years in the shadow of the Power Mac G5 | publisher = MacWorld | access-date = September 7, 2017 | archive-date = September 7, 2017 | archive-url = https://web.archive.org/web/20170907081048/https://www.macworld.com/article/2042702/ten-years-in-the-shadow-of-the-power-mac-g5.html | url-status = live }}</ref>

== Introduction ==
Officially launched as part of [[Steve Jobs]]' [[Stevenote|keynote presentation]] at the [[Worldwide Developers Conference]] in June 2003, the Power Mac G5 was introduced with three models, sharing the same physical case, but differing in features and performance. Although somewhat larger than the G4 [[Computer tower|tower]] it replaced, the necessity for a complex cooling system meant that the G5 tower had room inside for only one optical drive and two hard drives.

Steve Jobs stated during his keynote presentation that the Power Mac G5 would reach 3&nbsp;GHz "within 12 months." This would never come to pass; after three years, the G5 only reached 2.7&nbsp;GHz before it was replaced by the Intel [[Xeon]]-based [[Mac Pro]], which debuted with processors running at speeds of up to 3&nbsp;GHz.

During the presentation, Apple also showed [[Virginia Tech]]'s [[macOS|Mac OS X]] [[computer cluster]] [[supercomputer]] (a.k.a. supercluster) known as ''[[System X (supercomputer)|System X]]'', consisting of 1,100 Power Mac G5 towers operating as processing nodes. The supercomputer managed to become one of the top five supercomputers that year. The computer was soon dismantled and replaced with a new cluster made of an equal number of [[Xserve G5]] rack-mounted servers, which also used the G5 chip running at 2.3&nbsp;GHz.

== PowerPC G5 and the IBM partnership ==
[[File:Apple Power Macintosh G5 Late 2005 01.jpg|thumb|left|The inside of a Power Mac G5, late 2005 model]]
[[File:Apple Power Macintosh G5 2003 7982.jpg|thumb|The inside of an air-cooled dual-processor 2003 model]]

{{unsourced section|date=June 2025}}

The PowerPC G5 (called the PowerPC 970 by its manufacturer, [[IBM]]) is based upon IBM's 64-bit [[POWER4]] microprocessor. At the Power Mac G5's introduction, Apple announced a partnership with IBM in which IBM would continue to produce PowerPC variants of their POWER processors. According to IBM's Dr. John E. Kelly, "The goal of this partnership is for Apple and IBM to come together so that Apple customers get the best of both worlds, the tremendous creativity from the Apple corporation and the tremendous technology from the IBM corporation. IBM invested over US$3 billion in a new lab to produce these large, 300&nbsp;mm wafers." This completely automated facility in [[East Fishkill, New York]] figured heavily in IBM's larger microelectronics strategy.

The original PowerPC 970 had 50 million transistors and was manufactured using IBM CMOS 9S at 130 [[nanometer|nm]] fabrication process. CMOS 9S is the combination of [[Silicon on insulator|SOI]], low-k dielectric insulation, and copper interconnect technology, which were invented at IBM research in the mid-1990s. Subsequent revisions of the "G5" processor have included IBM's PowerPC 970FX (same basic design on a 90&nbsp;nm process), and the PowerPC 970MP (essentially two 970FX cores on one die). Apple refers to the dual-core PowerPC 970MP processors as either the "G5 Dual" (for single-socket, dual-core configurations), or Power Mac G5 Quad (for [[Central processing unit|dual-socket]], four-core configurations).

== Architecture ==
[[File:PPC-970fx.jpg|thumb|The PowerPC 970FX inside a PowerMac G5.]]
The Power Mac G5 line in 2006 consisted of three, dual-core PowerPC G5 configurations, which can communicate through its [[HyperTransport]] at half its internal clock speed. Each processor in the Power Mac G5 has two unidirectional [[32-bit]] pathways: one leading to the processor and the other from the processor. These result in a total bandwidth of up to 20&nbsp;GB/s. The processor at the heart of the Power Mac G5 has a "[[superscalar]], superpipelined" execution core that can handle up to 216 in-flight instructions, and uses a [[128-bit]], 162-instruction [[SIMD]] unit ([[AltiVec]]).

All modern 32-bit x86 processors since the [[Pentium Pro]] have the [[Physical Address Extension]] (PAE) feature, which permits them to use a 36-bit physical memory address to address a maximum of 2<sup>36</sup> bytes (64 gigabytes) of [[physical memory]], while the PowerPC 970 processor is capable of addressing 2<sup>42</sup> bytes (4 [[terabyte]]s) of physical memory and 2<sup>64</sup> bytes (16 [[exabyte]]s) of [[virtual memory]]. Due to its [[64-bit]] processor (and 42-bit [[Memory management unit|MMU]]), the final revision of the Power Mac G5 can hold 16&nbsp;GB of [[DDR2 SDRAM|Dual-Channel DDR2 PC4200]] RAM using eight memory slots, with support for [[Error-correcting code|ECC]] memory.

== Product revision history ==

[[File:Apple GeForce 6800 Ultra DDL Mac.jpg|alt=Apple Nvidia GeForce 6800 Ultra DDL 256MB AGP for Power Mac G5 M9593G/A|thumb|Apple Nvidia GeForce 6800 Ultra DDL 256MB AGP for Power Mac G5 M9593G/A]]

* 2003 June: Initial release at speeds of Single 1.6, Single 1.8, Dual 2.0&nbsp;GHz.
* 2003 November: Dual 1.8 replaces Single 1.8&nbsp;GHz; price reduction on Single 1.6&nbsp;GHz.
* 2004 June: 90&nbsp;nm Dual 1.8, Dual 2.0 and Dual 2.5&nbsp;GHz replace all previous models. The 2.5&nbsp;GHz model is notable as the first major PC with [[Water cooling#Computer usage|liquid cooling]] included as stock.
* 2004 October: A new Single 1.8 reintroduced, with a slower, 600&nbsp;MHz HyperTransport, PCI bus, based upon the [[iMac G5]]'s architecture (U3lite and Shasta chips). Apple's official name for this machine is "Power Mac G5 (Late 2004)".
* 2005 April: CPU speed increased: Dual 2.5&nbsp;GHz → Dual 2.7&nbsp;GHz (PCI-X, more reliable [[Water cooling#Computer usage|liquid cooling]]), Dual 2.0&nbsp;GHz → Dual 2.3&nbsp;GHz (PCI-X), Dual 1.8&nbsp;GHz → Dual 2.0&nbsp;GHz (PCI). Newly introduced features were the 16x dual-layer SuperDrives across the line and increased storage, up to 800&nbsp;GB for the higher-end models. The 1.8&nbsp;GHz Single was not modified.
* 2005 June–July: The Single 1.8 model was discontinued in the United States and Europe.
* 2005 October: Shift to dual-core processors: Dual 2.0&nbsp;GHz → DC 2.0&nbsp;GHz, Dual 2.3&nbsp;GHz → DC 2.3&nbsp;GHz, Dual 2.7&nbsp;GHz → Dual DC 2.5&nbsp;GHz (termed a Quad Power Mac G5, with four CPU execution cores), all with DDR2 memory, and [[PCI Express]] expansion in place of [[PCI-X]].<ref>{{cite web|date=October 19, 2005|title=Apple Introduces Power Mac G5 Quad & Power Mac G5 Dual|url=https://www.apple.com/newsroom/2005/10/19Apple-Introduces-Power-Mac-G5-Quad-Power-Mac-G5-Dual/|access-date=June 27, 2009|publisher=[[Apple Inc.]]|archive-date=October 9, 2017|archive-url=https://web.archive.org/web/20171009094135/https://www.apple.com/newsroom/2005/10/19Apple-Introduces-Power-Mac-G5-Quad-Power-Mac-G5-Dual/|url-status=live}}</ref><ref>{{cite web |url=http://www.computerworld.com/softwaretopics/os/macos/story/0,10801,106263,00.html |title=The Power Mac G5 Quad: Seat belt not included |access-date=June 27, 2008 |last=Kossovsky |first=Yuval |date=November 16, 2005 |work=[[Computerworld]] |publisher=[[International Data Group]] |archive-date=June 29, 2008 |archive-url=https://web.archive.org/web/20080629231527/http://www.computerworld.com/softwaretopics/os/macos/story/0,10801,106263,00.html |url-status=live }}</ref><ref>{{cite web |url=http://www.macworld.com/article/48071/2005/11/quadreview.html |title=Power Mac G5 Quad: Fast performance at its core |access-date=June 27, 2008 |last=Norr |first=Henry |date=November 22, 2005 |work=[[Macworld]] |publisher=[[International Data Group]] |archive-date=June 19, 2008 |archive-url=https://web.archive.org/web/20080619144840/http://www.macworld.com/article/48071/2005/11/quadreview.html |url-status=live }}</ref> The older PCI-X, Dual 2.7&nbsp;GHz model remained available for a while, but the slower speed single-core models were discontinued immediately.
* 2006 August: The Power Mac is replaced by its Intel successor, the [[Mac Pro]].

== Technical specifications ==
{{All are obsolete}}

{| class="wikitable mw-collapsible" style="font-size:small; text-align:center"
! colspan=2 | Model
! colspan=4 style="background:#FF9999" | Mid 2003<ref>{{Cite mac |model=Power Mac G5 |appleNumber=SP96 |everyURL=powermac_g5/index-powermac-g5.html |accessdate=March 10, 2023}}</ref>
! colspan=5 style="background:#FF9999" | Late 2004<ref name="Mid and Late 2004">{{Cite web |title=Power Mac G5 (Late 2004) - Technical Specifications |url=https://support.apple.com/kb/SP67?viewlocale=en_US&locale=en_US |access-date=2023-03-10 |website=support.apple.com}}</ref><ref>{{Cite web |title=Apple Power Macintosh G5 1.8 DP (PCI) Specs |url=https://everymac.com/systems/apple/powermac_g5/specs/powermac_g5_1.8_dp_2.html |website=EveryMac.com}}</ref>
! colspan=3 style="background:#FF9999" | Early 2005<ref>{{Cite web |title=Power Mac G5 (Early 2005) - Technical Specifications |url=https://support.apple.com/kb/SP46?locale=en_US |access-date=2023-03-10 |website=support.apple.com}}</ref>
! colspan=3 style="background:#FF9999" | Late 2005<ref>{{Cite web |title=Power Mac G5 (Late 2005) - Technical Specifications |url=https://support.apple.com/kb/SP37?locale=en_US |access-date=2023-03-10 |website=support.apple.com}}</ref>

|-
! colspan=2 | Codename
| colspan=4 | "Omega, Q37"
| colspan=5 | "Niagara, Q77, Q78"
| colspan=3 {{N/a}}
| colspan=3 | "Cypher"

|-
! rowspan=2 | Timetable
! Released<ref name="EveryMacG5">{{Citation |title=Apple Power Mac G5 Specs (All Power Macintosh G5 Technical Specs): EveryMac.com |url=https://everymac.com/systems/apple/powermac_g5/index-powermac-g5.html |access-date=2022-04-01 |archive-url=https://web.archive.org/web/20220401114713/https://everymac.com/systems/apple/powermac_g5/index-powermac-g5.html |url-status=live |archive-date=April 1, 2022}}</ref>
| colspan=3 | June 23, 2003
| November 18, 2003
| colspan=4 | June 9, 2004
| October 19, 2004
| colspan=3 | April 27, 2005
| colspan=3 | October 19, 2005

|-
! Discontinued<ref name=EveryMacG5/>
| June 9, 2004
| November 18, 2003
| colspan=2 | June 9, 2004
| colspan=4 | April 27, 2005
| June 13, 2005
| colspan=3 | October 19, 2005
| colspan=3 | August 7, 2006

|-
! rowspan=3 | Model
! Model number 
| colspan=8 | A1047
| A1093
| colspan=3 | A1047
| colspan=3 | A1117

|-
! Model identifier
| colspan=4 | PowerMac7,2
| colspan=4 | PowerMac7,3
| PowerMac9,1
| colspan=3 | PowerMac7,3
| colspan=3 | PowerMac11,2

|-
! Order number
| M9020
| M9031
| M9032
| M9393
| M9494
| M9454
| M9455
| M9457
| M9555
| M9747
| M9748
| M9749
| M9590
| M9591
| M9592

|-
! rowspan=4 | Performance
! [[Central processing unit|Processor]]
! colspan=2 | Single [[PowerPC 970]] (G5)
! colspan=2 | Dual [[PowerPC 970]] (G5)
! colspan=4 | Dual  [[PowerPC 970FX]] (G5)
! Single [[PowerPC 970FX]] (G5)
! colspan=3 | Dual [[PowerPC 970FX]] (G5)
! colspan=2 | Single Dual-core [[PowerPC 970MP]] (G5)
! Two Dual-core ("Quad-core") [[PowerPC 970MP]] (G5)
|-
! [[Clock speed]]
| 1.6&nbsp;GHz
| 1.8&nbsp;GHz
| 2.0&nbsp;GHz
| colspan=3 | 1.8&nbsp;GHz
| 2.0&nbsp;GHz
| 2.5&nbsp;GHz
| 1.8&nbsp;GHz
| 2.0&nbsp;GHz
| 2.3&nbsp;GHz
| 2.7&nbsp;GHz
| 2.0&nbsp;GHz
| 2.3&nbsp;GHz
| 2.5&nbsp;GHz

|-
! [[CPU cache|Cache]]
| colspan=12 | 64&nbsp;KB (instruction), 32&nbsp;KB (data) L1, 512&nbsp;KB L2
| colspan=3 | 64&nbsp;KB (instruction), 32&nbsp;KB (data) L1, 1.0&nbsp;MB L2 per core

|-
! [[HyperTransport]]
| colspan=4 | 800, 900, Dual 900&nbsp;MHz, or Dual 1&nbsp;GHz (2:1)
| colspan=4 | Dual 900&nbsp;MHz, Dual 1, or Dual 1.25&nbsp;GHz (2:1)
| 600&nbsp;MHz (3:1)
| Dual 1&nbsp;GHz (2:1)
| Dual 1.15&nbsp;GHz (2:1)
| Dual 1.35&nbsp;GHz (2:1)
| Dual 1&nbsp;GHz (2:1)
| Dual 1.15&nbsp;GHz (2:1)
| Dual 1.25&nbsp;GHz (2:1)

|-
! rowspan=3 | [[Random access memory|Memory]]
! Amount
| 256&nbsp;MB
| colspan=3 | 512&nbsp;MB
| colspan=2 | 256&nbsp;MB
| colspan=2 | 512&nbsp;MB
| 256&nbsp;MB
| colspan=6 | 512&nbsp;MB
|-
! Type
| PC-2700 DDR SDRAM
| colspan=3 | PC-3200 DDR SDRAM
| PC-2700 DDR SDRAM
| colspan=7 | PC-3200 DDR SDRAM
| colspan=3 | PC2-4200 DDR2 SDRAM
|-
! Maximum
| ''{{Gray|Expandable to 4&nbsp;GB}}''
| colspan=3 | ''{{Gray|Expandable to 8&nbsp;GB}}''
| colspan=2 | ''{{Gray|Expandable to 4&nbsp;GB}}''
| colspan=2 | ''{{Gray|Expandable to 8&nbsp;GB}}''
| colspan=2 | ''{{Gray|Expandable to 4&nbsp;GB}}''
| colspan=2 | ''{{Gray|Expandable to 8&nbsp;GB}}''
| colspan=3 | ''{{Gray|Expandable to 16&nbsp;GB}}''

|-
! rowspan=2 | [[Computer graphics|Graphics]]
! Type
| colspan=4 | [[NVIDIA GeForceFX 5200 Ultra]], GeForce 6800 Ultra DDL, ATI Radeon 9600 Pro, or Radeon 9800 Pro
| colspan=3 | [[NVIDIA GeForceFX 5200 Ultra]]
| [[ATI Radeon 9600 XT]]
| [[NVIDIA GeForceFX 5200 Ultra]]
| colspan=2 | [[ATI Radeon 9600]]
| [[ATI Radeon 9650]]
| [[NVIDIA GeForce 6600 LE]]
| colspan=2 | [[NVIDIA GeForce 6600]]
|-
! VRAM
| colspan=4 | 64, 128, or 256&nbsp;MB DDR RAM
| colspan=3 | 64&nbsp;MB DDR RAM
| 128&nbsp;MB DDR RAM
| 64&nbsp;MB DDR RAM
| colspan=2 | 128&nbsp;MB DDR RAM
| 256&nbsp;MB DDR RAM
| 128&nbsp;MB GDDR RAM
| colspan=2 | 256&nbsp;MB GDDR RAM

|-
! rowspan=2 | Storage
! [[Hard drive]]
| 80&nbsp;GB [[Serial ATA]] 7200-rpm
| colspan=3 | 160&nbsp;GB [[Serial ATA]] 7200-rpm
| colspan=2 | 80&nbsp;GB [[Serial ATA]] 7200-rpm
| colspan=2 | 160&nbsp;GB [[Serial ATA]] 7200-rpm
| 80&nbsp;GB [[Serial ATA]] 7200-rpm
| 160&nbsp;GB [[Serial ATA]] 7200-rpm
| colspan=2 | 250&nbsp;GB [[Serial ATA]] 7200-rpm
| 160&nbsp;GB [[Serial ATA]] 7200-rpm
| colspan=2 | 250&nbsp;GB [[Serial ATA]] 7200-rpm

|-
! [[Optical drive]]
| colspan=4 | 4x [[SuperDrive]] 4x/8x/16x/8x/32x DVD-R/CD-RW
| colspan=5 | 8x [[SuperDrive]] 8x/10x/24x/10x/32x DVD-R/CD-RW
| colspan=6 | 16x [[SuperDrive]] DVD+R DL/DVD±RW/CD-RW

|-
! rowspan=4 | Peripherals
! Connectivity
| colspan=9 | {{Gray|Optional [[AirPort]] Extreme 802.11b/g (external antenna)}}<br/>[[Gigabit Ethernet]]<br/>56k V.92 modem<br/>{{Gray|Optional on Late 2004 model}}<br/>{{Gray|Optional [[Bluetooth]] 1.1}}
| colspan=3 | {{Gray|Optional [[AirPort]] Extreme 802.11b/g (external antenna)}}<br/>[[Gigabit Ethernet]]<br/>{{Gray|Optional 56k V.92 modem<br/>Optional [[Bluetooth]] 2.0+EDR}}
| colspan=3 | {{Gray|Optional [[AirPort]] Extreme 802.11b/g (internal antenna) with [[Bluetooth]] 2.0+EDR card}}<br/>2x [[Gigabit Ethernet]]<br/>{{Gray|Optional 56k V.92 USB modem}}

|-
! rowspan=2 | Expansion slots
| colspan=4 | 3x 33&nbsp;MHz 64-bit [[Peripheral Component Interconnect|PCI]]<br/>1x 8x [[Accelerated Graphics Port|AGP]] Pro (1.6&nbsp;GHz)
| colspan=4 | 3x 33&nbsp;MHz 64-bit PCI <br/>1x 8x AGP Pro (1.8&nbsp;GHz)
| rowspan=2 | 3x 33&nbsp;MHz 64-bit PCI <br/>1x 8x AGP Pro
| colspan=3 | 3x 33&nbsp;MHz 64-bit PCI <br/>1x 8x AGP Pro (2.0&nbsp;GHz)
| colspan=3 rowspan=2 | 2x [[PCI Express]] x4<br/>1x PCI Express x8<br/>1x PCI Express x16
|-
| colspan=4 | 2x 100&nbsp;MHz 64-bit [[PCI-X]]<br/>1x 133&nbsp;MHz 64-bit PCI-X<br/>1x 8x AGP Pro (1.8&nbsp;GHz single+)
| colspan=4 | 2x 100&nbsp;MHz 64-bit PCI-X<br/>1x 133&nbsp;MHz 64-bit PCI-X<br/>1x 8x AGP Pro (2.0&nbsp;GHz+)
| colspan=3 | 2x 100&nbsp;MHz 64-bit PCI-X<br/>1x 133&nbsp;MHz 64-bit PCI-X<br/>1x 8x AGP Pro (2.3&nbsp;GHz)

|-
! Peripherals
| colspan=12 | 3x [[USB]] 2.0<br/>2x [[FireWire]] 400<br/>1x FireWire 800<br/>Built-in mono speaker<br/>1x Audio-in mini-jack<br/>2x Audio-out mini-jack<br/>1x Optical S/PDIF (Toslink) input<br/>1x Optical S/PDIF (Toslink) output
| colspan=3 | 4x USB 2.0<br/>2x FireWire 400<br/>1x FireWire 800<br/>Built-in mono speaker<br/>1x Audio-in mini-jack<br/>2x Audio-out mini-jack<br/>1x Optical S/PDIF (Toslink) input<br/>1x Optical S/PDIF (Toslink) output
|-
! rowspan="2" |Operating System
!Original
| colspan="4" |[[Mac OS X Jaguar|Mac OS X 10.2.7]] "Jaguar"
| colspan="4" |[[Mac OS X Panther|Mac OS X 10.3.4]] "Panther"
|[[Mac OS X Panther|Mac OS X 10.3.5]] "Panther"
| colspan="3" |[[Mac OS X Tiger|Mac OS X 10.4]] "Tiger"
| colspan="3" |[[Mac OS X Tiger|Mac OS X 10.4.2]] "Tiger"
|-
!Maximum
| colspan="15" | [[Mac OS X Leopard|Mac OS X 10.5.8]] "Leopard"
|-
! colspan=2 | Weight
| colspan=4 | {{Convert|39.2|lb|abbr=on}}
| colspan=4 | {{Convert|44.4|lb|abbr=on}}
| {{Convert|36|lb|abbr=on}}
| colspan=3 | {{Convert|44.4|lb|abbr=on}}
| colspan=3 | {{Convert|44.5|-|48.8|lb|abbr=on}}

|}

== Defects ==
[[File:Apple Power Macintosh G5 Late 2005 03.jpg|thumb|right|The back of a late 2005 model.]]
Early versions of dual processor G5 computers have [[Noise (electronics)|noise]] problems. The first one is [[Ground loop (electricity)|ground loop]]-based interference,<ref>{{cite web |url=http://docs.info.apple.com/article.html?artnum=86655 |title=Macintosh: Solutions for noise in the audio signal |access-date=June 27, 2008 |date=December 16, 2004 |publisher=[[Apple Inc.]] |archive-date=May 8, 2008 |archive-url=https://web.archive.org/web/20080508100457/http://docs.info.apple.com/article.html?artnum=86655 |url-status=live }}</ref> which sometimes causes noise leaks into the analog audio outputs. This bug was fixed in Rev. B G5.

The second noise problem came from the 'chirping' sound, which can be triggered by fluctuations in power draw. For example, using [[Mission Control (macOS)|Exposé]] causes a brief chirp.<ref>{{Cite news|url=https://arstechnica.com/staff/2006/03/3059/|title=Apple versus the analog monster|work=Ars Technica|access-date=2018-01-17|language=en-us|archive-date=January 18, 2018|archive-url=https://web.archive.org/web/20180118064650/https://arstechnica.com/staff/2006/03/3059/|url-status=live}}</ref> A widely circulated work-around is to disable the CPUs' "nap" feature using Apple's [[CHUD Tools]], but this was not recommended by Apple. This noise problem was not fixed until the dual core generation of G5s was produced, however it did not affect the "Late 2004" model (at least there have never been any reports). The power draw fluctuation was later attributed to the lack of power management features in the single-core processors.<ref>{{cite web |url=http://www.xlr8yourmac.com/g5/G5_noise_tips.html |title=G5 owner Feedback on Noises, CHUD Tools Nap mode Fix |access-date=October 23, 2008 |date=September 30, 2003 |publisher=Accelerate Your Mac |archive-date=May 11, 2008 |archive-url=https://web.archive.org/web/20080511201719/http://www.xlr8yourmac.com/G5/G5_noise_tips.html |url-status=dead }}</ref> Apple eventually posted the chirping bug information on its support site.<ref>{{cite web |url=https://support.apple.com/TS2033 |title=Power Mac G5: I hear buzzes, beeps, or humming |access-date=June 27, 2008 |date=September 1, 2005 |publisher=[[Apple Inc.]] |archive-date=January 25, 2022 |archive-url=https://web.archive.org/web/20220125055900/https://support.apple.com/en-us/TS2033 |url-status=live }}</ref>

Although the noise problems did not prevent the affected computers from working, they were problematic for audio professionals and enthusiasts, especially for the liquid-cooled models, which had been expressly designed as mechanically quiet for discerning listeners.

A common problem among single processor G5s was the cyclic expansion and contraction of a metal plate soldered to the Logic Board connecting all eight of the RAM slots. Eventually, this can cause the computer to no longer detect the RAM, and refuse to boot. Fixes for this include having the plate re-soldered, or exposing the other side of the Logic Board to heat from a heat gun. The latter option is far easier, since it requires neither soldering nor the removal of the Logic Board from the computer.

All 2.5&nbsp;GHz and 2.7&nbsp;GHz dual processor models and the 2.5&nbsp;GHz quad-processor model had a liquid cooling system that consisted of a radiator, coolant pump, and heat exchangers bolted to the processors. The cooling system was made by [[Delphi Automotive]], a former [[Harrison Radiator Corporation|Harrison Radiator Division]] of [[General Motors]]. This was a bold step for Apple, and should have allowed the use of very fast processors, giving Apple an advantage in both performance and reliability, but the system turned out to be subject to coolant leakage, made worse by the system's use of GM Dexcool coolant, which is more corrosive than regular automotive coolant.<ref name="PowerMac G5 Coolant Leaks/Repairs">{{cite web |url=http://www.xlr8yourmac.com/systems/G5_coolant_leaks.html |title=PowerMac G5 Coolant Leaks/Repairs. |access-date=July 15, 2013 |publisher=XLR8yourmac |archive-date=June 26, 2017 |archive-url=https://web.archive.org/web/20170626164703/http://www.xlr8yourmac.com/systems/G5_coolant_leaks.html |url-status=live }}</ref> If not caught in time, the leakage could destroy the processors, logic board, power supply unit, and even corrode the aluminum casing itself. While leakage was sometimes detectable by drops of green coolant in or beneath the machine, in many{{vague|date=February 2013}} machines the seepage is so slight that it was almost impossible to detect without dismantling the entire computer. Only the 2.7&nbsp;GHz model was equipped with a [[Panasonic]] liquid cooling system which was much more reliable.<ref name="PowerMac G5 Coolant Leaks/Repairs"/>

The liquid cooling system fits into the case where the heat sinks would normally go, so there is no easy way to distinguish the liquid-cooled versions from the air-cooled, although most, but not all,{{vague|date=February 2013}} of the liquid-cooled machines have a sticker inside warning about the possibility of leakage.{{Citation needed|date=November 2020}}

== P.A. Semi's G5 derivative ==
When [[P.A. Semi]] announced the preliminary pre-production plan of [[PWRficient]] processor,<ref>{{cite web |url=http://www.eetimes.com/news/latest/showArticle.jhtml?articleID=172303041 |title=PowerPC play: He shoots ... |access-date=June 27, 2008 |last=Merritt |first=Rick |date=October 24, 2005 |work=[[EE Times]] |publisher=[[United Business Media]] |archive-date=March 5, 2012 |archive-url=https://web.archive.org/web/20120305220857/http://www.eetimes.com/news/latest/showArticle.jhtml?articleID=172303041 |url-status=live }}</ref> there had been persistent rumors that Apple would prepare for its use in its professional line of personal computers.<ref>{{cite web |url=http://www.linleygroup.com/npu/Newsletter/wire051110.html |title=The Linley Group |access-date=June 27, 2008 |last=Gwennap |first=Linley |author2=Bob Wheeler |author3=Jag Bolaria |author4=Joseph Byrne |date=November 10, 2005 |work=The Linley Wire |publisher=The Linley Group |url-status=dead |archive-url=https://web.archive.org/web/20080819151249/http://www.linleygroup.com/npu/Newsletter/wire051110.html |archive-date=August 19, 2008 |df=mdy-all }}</ref>

In 2006, ''[[The Register]]'' reported that [[P.A. Semi]] had formed a tight relationship with Apple, which would result in P.A. Semi promptly delivering processor chips for Apple's personal computer notebook line and possibly desktops.<ref>{{cite web |url=http://www.theregister.com/2006/05/19/pasemi_apple/ |title=Apple shunned superstar chip start-up for Intel |access-date=June 27, 2008 |last=Vance |first=Ashlee |author-link=Ashlee Vance |date=May 19, 2006 |work=[[The Register]] |archive-date=March 6, 2013 |archive-url=https://web.archive.org/web/20130306003732/http://www.theregister.co.uk/2006/05/19/pasemi_apple/ |url-status=live }}</ref> Even in 2006, Apple did not have a laptop version of the G5 processor. The processor that would run the personal computers was P.A. Semi's preliminarily proposed processor, [[PWRficient]] 1682M (PA6T-1682M). The version that would be sampled for pre-production at third quarter of 2006 was a 2&nbsp;GHz, dual-core CPU with two DDR2 memory controllers, 2&nbsp;MB of L2 cache, and support for 8 PCI Express lanes. The sampled chip also has lower heat intensity than Intel's [[Core Duo]], which gives off 9–31 W under normal load.

According to ''The Register'' article, P.A. Semi executives believed that they were all but assured of winning Apple's contract, and CEO [[Dan Dobberpuhl]] thought that Apple's hints of moving to Intel were just a persuading tactic. At the time, the companies were working for PWRficient software.

Despite the advantages of more compatible architecture, Apple moved to the Intel architecture officially for 'performance-per-watt' reasons. However, P.A. Semi would not be able to ship its low-power multicore product in volume until 2007, which, combined with P.A. Semi's status as a start-up company, seems to have been the final blow to the development of Power Mac computers. However, it was also speculated that Apple switched to Intel processor because Apple could no longer abide the constant delays in performance ramp up,<ref>{{cite web |url=https://arstechnica.com/news.ars/post/20051026-5486.html |title=P.A. Semi's major PowerPC announcement, and looking back at The Switch |access-date=June 27, 2008 |last=Stokes |first=Jon |date=October 26, 2005 |work=[[Ars Technica]] |archive-date=April 29, 2008 |archive-url=https://web.archive.org/web/20080429202322/http://arstechnica.com/news.ars/post/20051026-5486.html |url-status=live }}</ref> desired native [[Microsoft Windows|Windows]] compatibility, or it was Apple's strategy to shift its business focus away from desktop computing to [[iPod]] (and subsequently [[iOS (Apple)|iOS]]) development.

Apple acquired P.A. Semi in 2008,<ref>{{cite news|title=Apple Buys Chip Designer |work=[[Forbes]] |url=https://www.forbes.com/technology/2008/04/23/apple-buys-pasemi-tech-ebiz-cz_eb_0422apple.html |access-date=2008-04-23 |url-status=dead |archive-url=https://web.archive.org/web/20080424162510/http://www.forbes.com/technology/2008/04/23/apple-buys-pasemi-tech-ebiz-cz_eb_0422apple.html |archive-date=April 24, 2008 }}</ref> using P.A. Semi's engineering resources to develop ARM CPUs for their [[iPhone]], [[iPod Touch]], [[iPad]], and [[Apple TV (device)|Apple TV]] product lines; and would go on to eventually come full circle with [[Mac transition to Apple silicon|these designs replacing Intel chips]] in Macs in 2020.<ref>{{cite news
| title=A Little Chip Designed by Apple Itself
| url=https://www.nytimes.com/2010/02/02/technology/business-computing/02chip.html
| access-date=2010-02-02
| work=[[The New York Times]]
| first1=Ashlee
| last1=Vance
| first2=Brad
| last2=Stone
| date=2010-02-02
| archive-date=August 15, 2017
| archive-url=https://web.archive.org/web/20170815233431/http://www.nytimes.com/2010/02/02/technology/business-computing/02chip.html
| url-status=live
}}</ref>

The PA6T-1682M processor would later be used by the [[AmigaOne X1000]] personal computer.

== Supported operating systems ==
{| class="wikitable mw-collapsible style=" style="font-size: 100%"
|+ Supported macOS releases
|-
!OS release
!Mid 2003
!Late 2004
!Early 2005
!Late 2005
|-
![[Mac OS X Jaguar|10.2 Jaguar]]
|{{Ya|text=10.2.7}}
|{{n/a}}
|{{n/a}}
|{{n/a}}
|-
![[Mac OS X Panther|10.3 Panther]]
|{{Ya}}
|{{Ya|text=10.3.4}}
|{{n/a}}
|{{n/a}}
|-
![[Mac OS X Tiger|10.4 Tiger]]
|{{Ya}}
|{{Ya}}
|{{Ya}}
|{{Ya|text=10.4.2}}
|-
![[Mac OS X Leopard|10.5 Leopard]]{{R|group=Note|10.5PPCFinal}} 
|{{Ya}}
|{{Ya}}
|{{Ya}}
|{{Ya}}
|}

{{Reflist|group=Note|refs= <ref name="10.5PPCFinal">Mac OS X Leopard is the final release to support PowerPC Macs.</ref> }}

== Timeline ==
{{Timeline of Power Macintosh models}}

== See also ==
* [[List of Macintosh models grouped by CPU type]]

== Notes ==
{{Notelist}}
{{Reflist|30em}}

== External links ==
{{Commons category|Power Mac G5}}
*[https://arstechnica.com/old/content/2002/10/ppc970.ars Ars Technica: Inside the PowerPC 970]
*[https://arstechnica.com/wankerdesk/3q02/powerpc.html Ars Technica: A Brief Look at the PowerPC 970]
*[https://arstechnica.com/apple/reviews/2004/09/G5.ars Ars Technica Review: Power Mac G5 Dual 2.5 GHz]
*[https://web.archive.org/web/20120930005749/http://www.forevermac.com/2005/10/apple-power-macintosh-g5-quad-core-2-5-ghz/ Forevermac.com: The Power Mac G5 Quad Core 2.5 GHz]

{{Apple hardware since 1998}}

[[Category:Macintosh towers]]
[[Category:Power Macintosh|G5]]
[[Category:PowerPC Macintosh computers|G5]]
[[Category:Macintosh case designs]]
[[Category:64-bit computers]]
[[Category:Discontinued Apple Inc. products]]