Jesus Christ Jack, everyone explained it in simple terms and in basic math, you had to go and break out the graph on us...
So does this all really matter? Thats my question.
What I know for a fact --- there are no FSB problems with the Core 2 Duo or the C2Q at 2.67 GHz, those are myths
It is one thing to say 'nope, won't be a problem', it is another to prove it
Let me put it another way.... all one hears from the Inq, HardOCP, Xbitlabs, is how the FSB is crippling the C2D.... this is a load of rubbish.
I can take the FSB all the way down to 400 MHz, clock the multiplier up to 20 (i.e. 5x faster than the FSB) and NO bottlenecks. I kick the FSB down from 1067 to 800 MHz, then multiply up the CPU to 3.4 GHz, guess what --- NO bottle necks. So what does this say --- the C2D does not consume much bandwidth, the FSB at 1067 is more than plenty, and if you back extrapolate, there is enough for a 2.67 Kentsfield
...
Jack
And there is a simple explanation for that which must be shared so that AMD fans who bang that drum understand that HTT/CSI is not useful for Core 2 thus far and won't be so long as we remain on a single socket. Whether Intel get's CSI or not is of no concern at this point. They WILL need it on the server side (multiple sockets) but on the desktop side it's not an issue assuming they continue using a shared caching system.
You see Core 2 Duo's (And Core 2 Quad's) use the cache for each core to talk to one another (Coherency). The Cache speed is faster then any HTT Link (as it runs at the speed of the processor) there is next to no latency and sure as hell no bandwidth problems. So for desktop level processors Intel has it down pat with their shared cache technology.
Now one would think that because Core 2 Quad (Kentsfield) has 2 pairs cores on a single piece of silicone and 2 Cache's (1 for each pair of Core 2's as essentially it's two Core 2 Duo's on a single package) that you would run into FSB bandwidth limitations as the two Core 2 Duo that comprise the Core 2 Quad need to talk to each other via the FSB. Well Tom's Hardware did a preview on the Core 2 Quadro and tests the processor at 1066MHz FSB as well as 1333MHz FSB and found there to be no performance increase. This indicated that the FSB is not starving the processors for bandwidth which again shows that for Desktop level processing CSI (or HTT if Intel adopted it) would not give the Core 2 Duo or Quadro any benefit at this point in time (4 cores). Perhaps scaling to 8 cores or two CPU sockets would require Intel's CSI technology (not perhaps, high probability that it would) but we're not there yet.
So to make a long story short, these beauties scale in a linear fashion. Even above 4GHz I have yet to see a decline in scaling performance. It's soo linear that it's damn scary, but this is to be expected as the higher I clock the processor.. the higher the 4MB L2 Cache get's clocked as it's on die running at full speed (1:1).
Hope this explains why Core 2 scales so well and suffer no FSB limitations.