Originally posted by Booga
I think a dual-core Yonah will give a twin dual-core G5 a run for its money if you factor in motherboard chipsets, thermal limitations, etc. I still maintain, as I've said before, that four G5's will starve on the current motherboard designs, and that Apple historically has not done well designing northbridge/L3 cache designs. If four G5's starve, that means you're not going to be significantly better than the performance for two G5's.
Have to violently disagree with you. If an app has 4 threads, a dual 970mp PowerMac using the current G5 motherboard will destroy a Yonah desktop in performance, all of the 970mp cores each have 1 MB on-die L2 cache afterall.
Can't really think of any edge cases where a Yonah system would handle 4 threads better than a dual 970mp system. It simply has a lot more execution resources than a Yonah system would have. Spaghetti integer code perhaps. Memory-bound applications, I don't think so since the L2 cache will alleviate that.
And Yonah is looking to be at least, if not more, efficient as the G5 per clock cycle and rapidly scaling up. Unless you're doing heavy floating point or Altivec, I don't see the hypothetical G5 system being all that stellar in real-world performance, even if you throw four of them at the problem. In short, I don't agree that this would be a runaway win for either side, and it's certainly not "ludicrous".
The statement is for multithreaded performance. You can't get away from the fact the 4 cores are better than 2. It's a ludicrous statement to state otherwise. Really.
We all already know the relative weaknesses and strengths of the 2 processors. At the same clock rate, we would expect Yonah to be a little bit faster in integer (better OOOE and BPU), 970mp to be much faster in FPU, and 970mp faster in SIMD.
As for performance per Watt, and performance per square inch of case space, well, there's obviously no comparison there. Performance per dollar may be close, but if you factor in not having to design your own chipsets and ASICs, I think the Yonah will even win there.
Yes of course, Yonah is great at performance/watt. It will be wonderful for Apple and it's industrial design, but a Yonah laptop ain't going to be outrunning a quad-PPC PowerMac. It's not really a prudent comparison. From the beginning:
Originally posted by Existence
Don't worry...buy a Yonah Powerbook instead! For most things, a dualcore Yonah PowerBook should outrun Apple's quad-PPC PowerMacs. It will be the first time in 7 years that PowerBooks are faster than PowerMacs.
Yonah laptops running faster than quad-PPC Macs? Let's not exaggerate too much. I can see a single 2.3 GHz Sossaman outrunning a single 2.5 GHz 970mp, but a dual-core laptop outrunning a quad-PPC, that's apples vs oranges.
We know that a 970mp is slated to run at 2.5 GHz, and that a Yonah will run at 2.1, maybe 2.2 GHz. I'm hard pressed to believe that a 2.2 GHz Yonah will be faster than a 2.5 GHz 970mp in anything with one exception: spaghetti integer code. Maybe that is "most" things, but a quad-PPC PowerMac would be intrinsically a specialist machine designed to run digital content creation apps and other things that would make use of the machine. And "most" things likely aren't memory-bound edge cases either.
We even should have doubts that a 2.2 GHz Yonah laptop would even outrun the dual 2 GHz PowerMac G5 currently shipping (faster in integer, slower in FPU, maybe mixed in SIMD). By the time a Mac/Intel Yonah laptop ships, I would certainly hope that Apple would be shipping a dual 2.3 GHz PowerMac as its low-end Mac/PowerPC pro desktop, making it quite debatable for a Yonah laptop to even outrun the low-end PowerMac Apple ships at the time, let alone a prospective high-end quad-PPC machine.
It's almost like saying a Yonah laptop will be faster than the dual 2.7 GHz PowerMac G5 Apple currently ships. That's pretty crazy when we know Yonah will only be at 2.2 GHz. It's ludicrous when we start saying a Yonah laptop will be faster than a quad-PPC like a dual 2.5 GHz 970mp system. One, it's not really an apt comparison. Two, a 970 is competitive to the P-M architecture at about the same clock rate and we already know that it clocks faster than P-M chips.
It's certainly nice that we can say a Mac/Intel Yonah laptop will be competitive to dual 2.0 to 2.3 GHz PowerMac G5 though. It'll run a full 30 fps for H.264/1080p video! Something I didn't think possible in a Mac laptop not 2 months ago.