[quote]Originally posted by Ed M.:
<strong>Amorph, I'm I'd have to agree with AirSluf on this one... Marketing.</strong><hr></blockquote>
Marketing would be stuck selling really expensive machines in a dying market. That's the problem.
Even with HT and RIO, NUMA architectures are expensive to implement. The fact that marketing would like
to sell 16 processor iMacs means nothing.
[quote]<strong>And if what you say is true, why even bother to develop a processor with outstanding SMP capabilities (and AltiVec) if all that hard work that went into the design will go unnoticed because it's not even being utilized?</strong><hr></blockquote>
First, the G4 was designed for up to 8 CPU SMP support. We never saw 8-way SMP PowerMacs.
Second, don't forget IBM, who will cheerfully put as many 970s as they please into their pricey RS/6000 line. The 970 was not produced exclusively for Apple, and the real cost of a 16-way 970 system can fit comfortably into IBM's enormous price brackets.
[quote]<strong>As I've stated before (and Programmer can back me up on this), SMP is the future.</strong><hr></blockquote>
I don't question that. But if you look at IBM, they're saying Cell is the future, and Cell is multiple cores per die. This removes a lot of expensive traces, and a lot of expensive logic, and numerous bandwidth bottlenecks, from the MP equation. IBM is planning on dozens
of cores per die down the line. So, as I said, Apple can scale up from two cores to dozens without significantly increasing the cost or complexity of their motherboard, which seems to me like a win-win situation. At that point, of course, you'll be able to buy RS/6000s (or whatever) that are effectively massively MP, with dozens of CPUs, each with dozens of cores, at something like the current price points (tens of thousands of dollars).
So I'm definitely thinking in terms of SMP. However, this involves processors
, not dies
, so you can easily have multiple processors (cores) per die and have SMP. It's not kinda-sorta-MP, like hyperthreading is (although future IBM cores will have that, too!).
[quote]<strong>As a matter of fact, it would be brilliant on their part if they invested heavily in a way where adding more than 2 CPUs is as simple as adding another backplane -- similar to the way mainframes do it.</strong><hr></blockquote>
There's a reason mainframes cost as much as they do.
The mainframes essentially have all the traces and support logic in place to accomodate a maximum number of CPUs, so you're talking about worst-case cost for the motherboard right up front. The daughtercard wouldn't cost all that much; the problem would be the board. Also, you'd be looking a great big board, and some really fancy work to provide a reliable, high-bandwidth connection of the CPU module to the board. None of this is impossible, of course, but as with hot-swappable PCI it's a matter of how much you want to pay for it.
If HT and RapidIO really make interconnects cheap, we might
see four chips. It depends on how soon, and in what quantity, IBM can provide multicore processors. Apple does want that $3500 price point back, I'm sure.
[quote]<strong>If you remember, IBM stated that their workstations employing the 970 were meant to be released as a 4-way config right from the start and I doubt that these systems will be in the 10k range.</strong><hr></blockquote>
Not all of them will. The pSeries UNIX servers start at $3500; the RS/6000 workstations start at about $8500 and go well over $10K.
IBM, after all. They sell machines that run up into the millions of dollars. They consider $10K to be entry level.
[ 02-07-2003: Message edited by: Amorph ]</p>