Originally posted by costique
I'm not defending Nr9, but it's possible and quite believable. I can imagine the situation like this:
I'm neither defending nor supporting Nr9, I just think he is either misunderstanding something or being mislead.
When IBM got 2.5GHz chips and realized that they're too hot (they may still be acceptably hot for IBM, but Steve said he's not buying chips any hotter), this instantly became a limitation #1. IBM engineers then had 2 big headaches: low yields and high power dissipation.
IBM has a problem but I see it as pushing to 90nm to fast and with too little innovation. IBM has pretty much demonstrated that they aren't ready to be a merchant supplier of processor chips. As far as the 970 and the 970FX neither chip could be considered an outstanding performer thermally.
With the current FX problems, people seem to forget there was a lot of SMOKE & MIRRORS with respect to the thermal performance of the 970. The question is simply this, is the thermal profile of the 970 industry leading with respect to computational performance. I would have to say that it is not so IBM clearly has room to grow in.
They worked on these and managed to improve yields somehow. However, better yields are money today while better power consumption is money tomorrow. They tried and tried and tried and yes, they have 3+GHz chips right now, which are either too few for a customer like Apple, or too hot for showmen like Steve, or just too unreliable in the long term. IBM can tweak the process more, of course, to squeeze a couple of MHz without sacrificing the far-from-excellent yields, but...
IBM can tweak the process, that is pretty much assumed. To make the gains they really need though they need to change to a revised 90nm process.
The dual-core version got so much closer during this struggle that it's probably more economically effective to launch PPC970MP now, than to delay it until they perfect the process so that you can stick a 3.5GHz PPC970FX into a pocket PC.
The MP is an interesting thought. Unless IBM can improve the thermal profile though the chip will be running extremely hot for a desktop PC. Think about possibly 140 watts or more. I suspect that the MP will be built on an improved 90nm process with that process eventually migrating back to the single core chips.
This does not mean we'll never see a PowerPC running at more than 2.5GHz. This only means that we may see a dual-core before the painful transition to 90nm culminates in higher clock rates.
As long as people realize that dual core is a solution to another problem we should be OK.
This only means that IBM engineers may find it easier and quicker to launch a dual-core 970 than to mass-produce any PPC at, say, 3GHz with their current technology.
The MP will come onto the market because it has to. That is there will be a very rapid migration to multiprocessing in the computing world due to one very important reality. That reality is that it is now possible to place more than one core on a die and remain economical. As I see it dual cores really have nothing to do with the current thermal and Hz limits. Multiprocessing is simply a way to make good use of the die space available to todays designers.
And this does not mean IBM suddenly stops maturing the process in favour of dual-core designs, because this same process (if I'm not totally off) will help them make faster both single and dual cores until they switch to 65nm. And if they do switch to 65nm in the near future is an 'if'.
What do you think?
I don't really think there is a big delta between what I suspect will happen and what you suspect will happen. The MP can be seen as introducing 90nm rev2 and much better thermal profiles. I expect this technology to be quickly applied to a laptop processor as it will allow acceptable battery lifetimes.