Place Your Bets Now About The Power Efficiency Of The Radeon RX 480 On Linux

[juno]

It is hard to predict how the market will react to APUs with HBM because this particular combination of technologies will be a new one. The question is whether people will be willing to pay ~300 EUR for an APU equipped with 4GB HBM for example.

No, most certainly they won't.
But I could see an APU with 1-2 HBM stacks for a lower price, and there where it makes sense. On the desktop, you have plenty space and power and there are not much applications yet that benefit from HSA, unified memory or higher bandwidth between CPU/GPU. So you'd rather take a decent CPU+GPU combination.

On a notebook, however things are different. There are plenty notebooks that don't use SO-DIMMs anymore but the RAM soldered directly onto the mainboard, so you can't upgrade either. It is smaller and easier for the OEM to build with to just one central die to implement and cool instead of adding a MXM module. Intel uses eDRAM for their Iris Pro parts, which is expensive, too. But that's more like a L4$, just 128 MiB max. And they have no graphics solution that could compare to something like 12+ GCN CUs (I think +50% for 14 compared to 28 nm seem legit).
An APU with 2-4 Zen Cores, 12 CUs and HBM would be premium. Intel has recommended customer prices of 490-1200 USD for their recent notebook CPUs with Iris Pro and they sell. Yes, I know no OEM is paying those prices, though.

It doesn't even have to be the full system memory with 16 GiB (however possible with two 8Hi-stacks), 1 stack would be enough as a start, compared to Intel's eDRAM.



I don't think one HBM stack and the small interposer would make this unaffordable. IMHO, "Premium OEMs" could be interested in something like this. Apple could even use that and push HSA, If they liked to...