That's like letting Netburst set the expectations for clock speed on Conroe.. Okay, not that extreme, but you get my point. Zen is going to be a wider/higher IPC design, the clock margins are going to be a different vs Excavator.
2nd last paragraph, - I agree to an extent.
But it's funny you mention Netburst vs conroe.. An extreme example as you say- but in reality it doesn't really give a good case for the point, as the outcome wasn't so extreme.
That was one of the stunning things about Conroe's launch. The clockspeeds at ambient temperatures (where it matters) wern't much lower than Netburst both factory and overclocked... Despite being so much shorter, wider, and with an IPC some 80 + % higher
and it really came down to Netburst's inherent frequency targets being just sooo far off reality for the available process' characterstics, that they barely out-clocked Conroe anyway in the confines of platform power limitations (3.73Ghz @115w vs 2.93Ghz@89w DC) - So ~20% more frequency, for all the massive architectural - IPC robbing compromises .
In stark contrast, Conroe hit the nail on head so to speak. its frequency targets were Perfectly suited to the Process tech
Constuction cores somehow fell into a similar trap as well. Designed around 32nm SOI, targeting >4Ghz frequencies, but they've since progressively changed focus, and in a similar vein to my Netburst example above, the compromises aren't yielding much frequency delta from a higher IPC deisgn anymore - at least not down in ~3Ghz region anyway.
So I guess the question is - Will this far less extreme scenario play out similar, and have an even less extreme outcome on clockspeeds?
To be honest I think the biggest potential for disapointment with reaching clockspeeds we're expecting will instead be the Process itself. So little information about it (at least that I am aware of) and what, if any variation there is to suit higher frequency?
I guess we'll never know the reality since XV will never be on the same process. but it would be nice to have some data on the two process nodes performance.