I don't speak German but if Google translation is to be trusted it mentions +30% performance at 15W, which is a bit odd since Kaveri starts at 17W for dual-cores and 19W for quads. It also seems to cite VR-Zone as a source but I see nothing on VR-Zone's website.
The interesting part is that there's only 2MB of L2, vs. 4MB on Kaveri. One wouldn't expect this unless there were some way of compensating for the loss of cache, namely HBM.
Potentially, the former provides guidance on the latter.
Cutting a quad core's power consumption that low probably leads to a lower clock ceiling, which reduces the impact of a miss.
The design is likely fighting for die space, given the addition of on-die IO and possible growth in other areas that had feature improvements. The L2 would have been a comparatively low-hanging fruit in buying a few mm2, and for that cherry-picked low power point, halving it might shave off a few fractions of a watt.
I'm also a bit skeptical of Carrizo's value at 12W where I'd expect low-power APUs (I think they're called Nolan and Amur) to do better.
Possibly because it's the only corner case where marketing can find a 30%.
AMD has to play in the low-end segment for APUs because they can't properly value the advantage of their iGPUs -> because the iGPUs lack in bandwidth -> because AMD has merely touched the issue of lack of bandwidth in iGPUs during the 3 years of APUs that we've had -> because apparently it's more profitable to just put all the money on discrete GPUs -> because they have to practice low-margins in their APUs -> because they can't properly value the advantage of their iGPUs -> because the iGPUs lack in bandwidth -> etc. etc.
Or bandwidth is a physically difficult and expensive problem to crack. If the rumors concerning GDDR5M are true, it's one that dead-ended a decent chunk of Kaveri's die.
Possibly, AMD's difficulty in deriving value from its advantage in IGPs is because the value of that advantage is being overblown. It has probably prevented Intel from completely obliterating AMD and all memory of it, and then salting the earth over the ashes, but there are limits to what it can do.
That the majority of x86 CPUs with graphics are Intel indicates way too much of the market doesn't care enough, and maximizing the value of the IGP as desired apparently only works if one discards the value of the money it won't bring, at least for that segment.
Yeah hopefully it means they got rid of the 3 different buses to the graphic parts.
Maybe they've implemented the filters or directory structures to allow for better concurrent accesses and caching to coherent memory, improving on Onion+.
There is mention of preemption, which HSA requires, and possibly there are other HSA requirements added.
We can go back and note that AMD's marketing for Kaveri was that it had "HSA features", so there are various requirements like preemption in the provisional specification that no current APU can meet.
