Re: Re: Re: Re: Re: Re: I hope so. At least we get to see Panther for sure...
Originally posted by eric_n_dfw
I have never heard this before - interesting.
Um, not from what I have heard. The 7400 series is based on the 604 (604e?) core, not the 603 or G3/750 core. It's not just a G3 with AltiVec bolted on.
I understand that you believe the 604 produced the 7400, but please allow me to provide some reasoning for my belief:
Performance-wise, the 604 was superior to the 603 in any way they were different. It had more execution units and a vastly superior floating point unit. When Arthur (740/750) came out, it was superior to the 603 in every way, but there were specific tasks, like floating point, where the 604 still rocked the kasbah. A 300MHz 750, if I recall correctly, was still underperforming in floating point to the 200MHz 604. So, this checks out -- it's reasonable to say the 750 came from 603, but not 604.
When the 7400 came out, there were small specific tasks where it outperformed the 750 (outside of Altivec code, which of course rocked Arthur's world). By and large, however, the 750 performed basically the same as a 7400. This helps me believe my opinion. I've read elsewhere that the 7400 was 603 derived, but borrowed a few elements from the 604 to help it do better than 750 -- in the real world, they were basically the same (setting aside Altivec for a moment).
If you're migrating a processor design from an old technology, it is far easier to only have to go one technology -- otherwise, you have to re-fix up your design each time you shrink. It would therefore be easier to take the 750 which was already migrated forward than the 604 which was 2 technologies behind. Power consumption was an issue with these processors -- the 7400 had to eventually go in laptops, and Moto's market is pretty power conscious. Due to the sheer amount of logic, the 603 derived 7400 (by way of the 750) would consume more power than a 604 derived 7400.
Please don't mistake me for someone who wouldn't have wanted to see a 604 derived 750 or 7400. I actually feel kinda cheated that the airplane DVD people and Moto's embedded customers are so important that we had to end the 604 family with Mach 5. (I've heard about a Mach 7 design that was shot down at Somerset that was basically the 604 with all the enhancements that took the 603 to the 750, so Mach 7 would have been like Arthur except with better floating point and execution.)
But I digress. I don't mean to belittle the 7400 by calling it 750 derived. It's certainly more than a 750 with Altivec bolted on -- but I think that would be the easiest way to explain that to a lay person. Altivec did so much for PowerPC non-server space that I don't think even saying that the "7400 was a 750 with Altivec bolted on" would be belittling in any way.
It appears that the 970 is a simplified Power4. If you want to get technical, therefore, shouldn't it be considered derived from generation 3.5 of the Power family?
Because I think the 970 will be much better than the 74xx family in most respects, I think it's reasonable to call it G5 from Apple's marketting perspective.
