Legend11 on 23 August 2007
Oops I misread your question and I see what you're getting at now... Why didn't Microsoft and Sony simply follow what Nintendo did rather than putting in new processors, gpus, etc. Microsoft went the way they did because they had a falling out with Nvidia. I'm not sure about Sony, I suspect they thought the Cell would put the PS3 far beyond Microsoft's console but didn't anticipate developers having problems and being slow to get up to speed with it.
