Originally posted by Yevgeny
So Programmer, what do you think the odds are for Apple to drop Altivec support from the G6 and to simply forward such calls to a dedicated Cell CPU? This would reduce the G6 complexity and cost. You could treat Cell like an old math coprocessor.
What is the one word that processor designers never mention when introducing their latest and greatest chips?Latency
This way the Power5 to G6 transition is simpler (no bolting on Altivec).
Given that they have at least 2 VMX implementations now, I don't see how that is a real problem. Especially with IBM's automated design tools.
This way it is easier to cram multiple cores into a single G6 die because you have reduced the complexity of each core.
Why have multiple G6 cores when you can have even more SPUs? Most problems that can be made parallel also benefit from using vector units.
This way you don't have oddly redundant Altivec units on both the main CPU and the Cell CPU.
People keeping saying "why have both" or "these are redundant"... but they are not
. There is good reason to have both and they fulfill different purposes.
This way you could probably squeeze some extre MHz out of the G6 because you don't have to time your communication with the Altivec registers/etc.
No more so than with the GPR/FPR files. The VMX unit doesn't slow down the chip -- you just have to look at all 9 cores on the Cell to see that!
Thoughts? I'm not up to date wrt the latest G6 rumors, all I know is that is is two cores on the die. [/B]
There are no G6 rumors. There are dual core G5 rumors. If I had to start one I'd say G6 == Cell.
BTW: IBM was an equal partner in the initial VMX development so I'm quite sure that they do not pay Motorola/Freescale (or Apple for that matter) a cent.