360 Slim's combined CPU-GPU chip shown, detailed
VentureBeat's posted an exhaustive feature on Vejle, 360 Slim's combined CPU-GPU processor, showing diagrams and explaining that how, by combining the two components, Microsoft and IBM were able to make substantial reductions in space, cost and power for the final machine, allowing Microsoft to add new features such as wireless networking at the same time.
The new combined chip has 372 million transistors, the basic on-off components of electronics.
IBM and another unnamed manufacturer are building the chip in a 45 micron silicon-on-insulator manufacturing process.
Why did Microsoft build a new chip for Slim? It's smaller, cheaper to produce and uses less power. Xbox 360's original processor (designed by IBM) and the original graphics chip (designed by AMD) were built using a 90-nanometer silicon-on-insulator process. The GPU in particular was prone to overheating to such an extent that it could warp the system board and result in unexpected console failures - you know this phenomenon as RROD.
Expect this to be an ongoing process. Reducing the size and cost of chips is an important part of an console manufacturer's strategy. For example, Sony was able to eventually combine PS2's two main chips into a single unit and reduce the overall size of the chips to 13 percent of the system's originals in 2000.
Embedded memory chip
360's new main chip is packaged with a separate 10Mb embedded memory chip, the two being packaged in a single module.
The combined chip uses 60 percent less power than the original 2005 pair of chips, and it uses 50 percent less space.
Vejle is the sixth Xbox 360 chip configuration, the former five being, from launch, the two 90 micron chip-sets in Xenon and Zephyr, then the three 65 micron sets in Falcon, Opus and Jasper.
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