PowerPC G4

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Motorola G4 processor, here a PowerPC 7400

PowerPC G4 is the name for the RISC - processors PowerPC 74xx of Motorola .

The name G4 alludes to the fourth generation ( “Generation Four” ) of PowerPC chips manufactured by Motorola. The design of the processors was developed in close cooperation between Apple , IBM and Motorola (AIM alliance), but IBM stayed away from the development. One of the reasons for this was different views on how the SIMD unit AltiVec should be integrated into the chip.

Before production was discontinued at the end of 2005, the G4 processors were mainly installed in the Power Mac and PowerBook model series by the American computer manufacturer Apple . G4 is therefore also the slang term for the various Power Mac G4 models. Motorola hived off the semiconductor division completely in 2004 to the subsidiary Freescale Semiconductor .

The successors of the G4 series are the G5 processors developed and produced only by IBM . Freescale itself has not yet developed the series further, but is focusing its progress in the embedded area, where, for example, additional external interfaces are being relocated to the chip, for example with the MPC8641D. At the same time, the name of the processor series was changed to e600, some of which are fully compatible with the G4 processors used by Apple.

technology

G4 processors contain a 128-bit vector unit ( SIMD process) called " AltiVec ". This unit is comparable to the SSE technology of the IA32 processors. This means that up to four floating point numbers can be processed at the same time, or up to 16 bytes . The multiprocessing capability has also been improved. The members of the previous G3 model series are capable of coupling multiple processors, but with severe performance restrictions. A fast chip-to-chip connection was therefore included in the architecture for the G4. The processor is said to have 33 million transistors.

Processors of the series

  • Motorola PowerPC 7400 - basic model
  • Motorola PowerPC 7410 - basic model for mobile use with increased processor and bus speeds
  • Motorola PowerPC 7440 - PowerPC 7450 for mobile use without L3 cache and with a lower core voltage
  • Motorola PowerPC 7450 - unofficially also known as G4 +, with increased processor and bus speeds

The fastest models so far are the 7448 with 1 MB L2 cache and max. 1.7 GHz (more with suitable cooling) and the 7457 with max. 2MB L3 cache and 1.33 GHz (the 1.42 GHz 7455 was only made for Apple).

Trivia

The Power Mac G4 from 1999 calculated too quickly to be allowed to be exported to China. Since its computing power just fell into the range of supercomputers defined at the time, it was subject to American export restrictions.

Individual evidence

  1. ↑ Tony Smith: Motorola upgrades PowerPC G4. In: The Register. Situation Publishing Limited, September 27, 2000, accessed May 17, 2010 .
  2. ↑ Tony Smith: Motorola uniquely low-power PowerPC G4 Plus. In: The Register. Situation Publishing Limited, May 22, 2001, accessed May 17, 2010 .
  3. ↑ Tony Smith: Apple preps 600MHz, 700MHz PowerBook update. In: The Register. Situation Publishing Limited, October 11, 2001, accessed May 17, 2010 .
  4. ↑ Andreas Beier: No Power Mac G4 for China. In: Heise online . Heinz Heise Verlag , October 27, 1999, accessed on January 24, 2009 .