Exophase (exophase.delete@this.gmail.com) on February 7, 2015 11:47 am wrote:
> Alberto (git.delete@this.git.it) on February 7, 2015 11:22 am wrote:
> > Umm yes, because they not say if the IPC increase claim is "mostly 10%" or "mostly 50%"
> > :), neither they say if the sustained increase in performance at the same power is "up to"
> > or "in average" or "in some lucky cases" or "in most cases" etc.....they are vague.
> > And yes some informations on test are welcomed.
>
> Peter's descriptions were clear and unambiguous, but obviously he is operating outside
> of official releases and there's a limit to what he can say - like giving large data sets
> of benchmark results. But I doubt anything would really be good enough for you.
>
> > Still i think the gain is mainly in the power management, not so strong in both A15 and A57.
>
> How exactly does a change in power management result in an increase in IPC by 10-50%?
> If all of the performance was gained by an increase in clock speed enabled by a decrease
> in power consumption you may have an argument, but that is clearly not the case.

I meant the topic of the slides, the performance at the same power. I could be wrong but the "IPC" is not even named.
The problem is that they not say the "workload", yes because there are thousands of workloads and many of them do not strees the cpu at all, allowing it to run at lower clock speeds (with the right power management) and at lower voltages. We all know like FInFet main strongness is at the lower voltages available (the gains are amazing !!!!) and they are ummm.....not so exciting but good enough as the voltage goes up.

So i am pretty certain that their claims are about an average handset usage without pretending much form the SOC. This is good!! being the more common situation in pratics.
Still as the things become serious, IMO all this gold becames silver, forget this gold with the SOC under full load !!!.

I am pretty in line with David, most of the advantage comes from the dramatic process shift.

>
> > This time they have worked like Qualcomm have done with its very power efficent Krait core line???
>
> Krait gets all this praise for being so power efficient but I have yet to see a real comparison with normalized
> performance on the same process and all that. All I've seen is comparisons where A15 uses more power (sometimes
> a lot more) while also performing better (sometimes a lot better). I repeat it constantly, but perf/W is
> not linear and these comparisons are meaningless. Reduce the clock speed on the A15 until it matches the
> performance on the Krait core and then do a fair measurement - of course, this will vary tremendously from
> benchmark to benchmark, especially since Krait appears to have some big glass jaws.
>
> What we do know is this: despite your remarks that power management is "not so strong" in A57 Qualcomm
> still preferred to use it instead of a version of Krait that only added ARMv8 support, something
> I'm sure they could have done in time if it would have given them such an advantage.
>

Sorry i have forgot your nickname :). This is a new thread, i not want to criticize further the topic of many others.
Ha! Samsung plans to leave ARM IP in both Cpu and Gpu :).