Editing Power Mac G4 (section)

=== Mirrored Drive Doors models ===
[[File:Apple PowerMac G4 M8570 MDD front.jpg|thumb|Power Mac G4 (Mirrored Drive Doors)]]

Another generation of Apple Power Mac G4s, officially named '''"Mirrored Drive Doors" (MDD)''', was introduced on August 13, 2002, featuring both a new [[Xserve]]-derived DDR motherboard architecture and a new case design. All models were available in dual processor configurations running at {{nowrap|867 MHz}}, {{nowrap|1 GHz}} or {{nowrap|1.25 GHz}}. As with the Xserves, the [[PowerPC]] 7455 CPU used does not have a DDR [[frontside bus]], meaning the CPU of the 133&nbsp;MHz [[frontside bus]] models could use at most only 50% of the new system's theoretical memory bandwidth, providing no improvement over previous models. The rest was available to the [[graphics card]] and [[input/output|I/O]] systems.

The early dual processor models generated more heat, and required more fans and larger heat sinks; the power supply fans were criticized for the increased noise, with third parties producing noise-reduction cases to dampen the sound in audio-sensitive environments. Apple released a firmware update to reduce fan noise and offered a fan and power supply exchange program.<ref name="macworld_2003_05">{{cite magazine|last=Shalat|first=Andrew|date=May 2003|title=The Silence of the Power Macs|magazine=[[Macworld]]|at=Mac Beat; p. 30}}</ref>

The last real update to the Power Mac G4 line came on January 28, 2003, offering dual 1.42&nbsp;GHz PowerPC 7455 processors, with features not seen in previous DDR models: a built-in FireWire 800 connector, optional integrated [[Bluetooth]], and optional integrated [[AirPort Extreme]]. These were also the first Power Macs that could not boot into [[Mac OS 9]].<ref name="macworld_2003_05_rev">{{cite magazine|last=Breen|first=Christopher|date=May 2003|title=1GHz and Dual-1.25GHz Power Mac G4s|magazine=[[Macworld]]|at=Reviews; pp. 36–37}}</ref>

With the launch of the [[Power Mac G5]] on June 23, 2003, Apple re-introduced the August 2002 Power Mac G4 because of perceived demand for Mac OS 9 machines. Between that, its low price-tag, and the delayed availability of Power Mac G5s, it proved a strong seller, albeit for a relatively short time. Production stopped on June 27, 2004, and the remaining inventory was liquidated, its discontinuation ending the 20-year legacy of Classic Mac OS support.