Its going to purely be a function of how well they are yielding because, as you point out, it doesn't look like it'll be driven by competition from AMD. The mid-3 GHz range seems achievable though.
Nehalem sounds like the more exciting chip because of the memory controller stuff.
Well, there's been hype about this in AMD chips for years...
The fact that its a whole new microarchitecture is the exciting part. Everybody has been clamoring for on-chip memory controllers for ages, but really I'm not sure how big a win it is in terms of performance in desktop systems. It should be a significant cost and TDP win since there are fewer parts, and it should reduce the amount of L2 cache they are obliged to include... but in terms of real-world performance due to the on-die memory controller alone, I don't think it'll live up to the hype around the issue. The new chip interconnect will be a nice addition at the MacPro level -- finally a competitor to HyperTransport... but again, on most software is it going to be a big win? The return of HyperThreading is also interesting for software that needs lots of threads, but really... with 4+ cores already are most users going to see a difference? Perhaps as software evolves over the next few years, but on the day these things ship I doubt it.
Well, I was wondering why I should wait for Nehalem when a quad or 8 way Penryn would surely do just fine. And surely, in light of current Mac Pros... Grr...the GPU is the more exciting prospect? A 9900 will seem very special after an Ati 1900 I would have thought? And in terms of 3D...Lightwave...the odd game, lots of Photoshopping, a quad or 8 core with a decent GPU would do me just fine.
Even most consumer Apple apps only seem to use 1 and a half cores half the time, heh. I think the big win is going to have to come from Software makers over the next few years.
Didn't programmers use to have to consider the chips in the Amiga? Are programmers just aiming for the 'middle ground' with their code? Are they writing lazy 'mono-thread' code..? Or do they just need to wait until Quad/Duo core reaches critical mass before they change the 'mhz' culture code?
I guess you can provide insight into that...
The GPU core tightly coupled to the CPU may be the most interesting technology. Intel has come a long way with their integrated GPUs, and I would guess that this thing is the next generation after the current X3100 and it will benefit from high speed interconnects with the CPU and the CPU's on-chip memory controller. There is no doubt that all the high-end GPU fans will slag this mercilessly just like they do the X3100 and its predecessors... but the fact remains that for the iMac and MacBook this will be a big step up. Possibly a very big step up.
Well, it seems Intel are coming round the mountain with GPUs. If they're going to exceed the x3100 then surely you'll have GPU performance in excess of a Nintendo Wii? Hey, don't knock it folks. Nintendo have bowed out the arms race and seem to be doing ok...
But that's one thing... Apple's Mac Pro's should not be bowing out the gpu arms race...heh. Jan 15th seems ages away...
What's Nehalem going to offer worth waiting a year for?
Yeah, that's my point. With Penyrn the transition to 45nm is a win, along with various architectural refinements... Nehalem is going to bring a bunch of new forward-looking stuff, but its not clear how big an improvement will be delivered on day 1.
But like many forward thinking things...we're not going to see the benefit until Quad core and maybe even 8core are mainstream? Most software seems to be only just emerging from the dark ages in terms of threading?
Looks at Photoshop. Apple demo'd funhouse as a real time filters app. Yet, did Adobe put that realtime functionality in? Nooooope.
Software makers have to get on board. Maybe it will be the 'Coco' Mac developing 'young guns' that will show what the Mac can really do now we have Leopard out.
Addendum: I just came across an Intel page discussing Nehalem, and the stuff it talks about is mostly of interest to Intel and PC makers. It is aimed at created a chip family that scales from the low end to the high end, from the low-power to the high-power. There is no discussion of specific performance enhancements or new technologies that should make a buyer wait for it. Laptops and AIO machines will benefit the most, it looks like.