Quote Originally Posted by Opteron146 View Post
Anybody who wants to speculate about clock rates ?

Just rememered IBMs 4.25 GHz p7 8core chip with 4xSMT. That is with 45nm

So far I thought 5 GHz for BD is fanboy dreaming, but compared to that monsterous 45nm chip it should be rather reasonable now that a smaller BD die produced in 32nm together with high-k interconnects should be able to achieve that.

What do you think ? Is it ok, to speculate on x86 clocks by comparing it to Power / RISC numbers ?

@informal:
I agree totally ;-)

Thanks
I will give it a try
@95W envelope we have 6 cores done on 45nm working @ 2.8Ghz. If BD was done on the same node I guess ,with the targeted 20% in clock speed due to pipeline changes, we could have 2.8x1.2=3.36 or round up to 3.4Ghz.BUT,it will go to 32nm highK/mg instead.I would still pick the same clock and power draw values just to be conservative(let's disregard the 45->32nm node improvement since we have 33% more cores).That's a 4 module part. Now,if count in 10-15% IPC improvement(pick average 12.5) and 33% more cores and at last divide by 1.1(10%) for the "performance hit" in fully loaded modules,in multithreaded workloads we get an equivalent performance of 4.65Ghz X6 Thuban .This is with no Turbo over stock.

Now,with the new Turbo(<=1/2 of the cores are idle,picking Thuban's Turbo conditions),I would expect ~20-30% clock increase,take a 25% as middle .We get => 3.4x1.25=4.25Ghz in poorly threaded or single threaded applications.Now add the speculated 10-15% IPC jump(pick 12.5 as arithm. mean value) to get the equivalent Thuban class core clock=> 4.25x1.125~=4.8Ghz Thuban in single threaded workloads(no 10% hit here).If the power gating happens in a way so that 2 modules are gated,we have the 10% hit due to core scaling in modules => 4.8/1.1=4.36Ghz Thuban class core speed in poorly threaded workloads(1<no. of threads active<=4).

So to sum it up,I expect a 95W 3.4Ghz "X8" Bulldozer model,with 4.25Ghz effective turbo and 10-15%(pick 12.5%) IPC jump. This would be equal to a:
-4.8Ghz Thuban in purely single threaded workloads and
-4.36Ghz Thuban class core in poorly threaded workloads.
-4.65Ghz X6 Thuban in multi thread workloads.

In the 125W range I would expect 3.6 and 3.8Ghz models,and if they really want to push the limit,a 4Ghz 125W model. Turbo would be smaller,percentage wise and similar or slightly lower frequency wise than in the earlier example. So effectively just add 0.2, 0.4 and 0.6Ghz on top of the 3 numbers for "equivalent Thuban" above and you will have projection how these 3 125 or 140W ones could perform(top model ,the hypothetical 125/140W 4Ghz one could easily be equivalent to 4.7-5.4Ghz Thuban class core,depending on the workload).
Enough of xtreme speculation from me