How are the layers communicating with each other, and how fast can they do it? Vertical communication will have to pass trough that layer of glue...
Same way they have done for nearly 10 years, with TSV. The following PDF is a economics feasibility study of the advantages and costs (Thanks to McHuj).
http://www.gsaglobal.org/events/2011/0331/docs/keynote_yuan_xie.pdf
In it concerns voiced by Rolf NM, DieH@rd and others are referenced. 3D stacking incurs a cost and a look at the benefits this gives vs the added costs is needed. It seems to me when reading the paper that there are several benefits.
1) Sony can design wafer layers containing devices that will be used in other platforms and wafers could be considered building blocks to put together CE platforms. The economy of scale then works across all of Sony. (Addressing is an issue in stacking identical wafers internal programmable?)
a) A 2 gig memory wafer could be used in TVs, Blu-ray and more with possible two wafers for a total of 4 gigs in a PS4. Same applies with one gig wafer stacking or any amount that fits their roadmap.
b) CPU wafers can have some amount like 4 to 8 SPUs per wafer with large L2 cache. Stack as many as needed.
c) GPU can be split into multiple wafers, stack as many as needed
The above, having wafers with fewer components and stacking fits DieH@rd's earlier post about yield efficiency. With smaller wafers and reducing the number of components on each wafer with testing, yields can increase reducing costs.
I just wonder at the heat dissipation with both GPU and CPU in one package. PS3 dropping two die sizes from 40nm to 28nm might be possible now in one 3D stacking package. Could a PS4 have to wait for 20nm to do the same? Is this the reason PS4 is coming later?
If/when Sony uses the same technique of 3D stacking with the PS3-RSX-memory-Southbridge/usb/lan/hdmi/audio in one chip they could get the PS3 price down incredibly low.
Kung Fu Grip said:
Respectable? Wasn't it that onlive lady that said one console manufacture will bow out at E3?
I can't see sony leaving the industry. MS either. But no PS4 rumors does scare me. Look how many MS ones we have already.
It's gotten expensive and it makes sense to share R&D so I don't have issues with Microsoft and Sony sharing SOME of the technology in a next generation game console. Sony needs a game console to use the economy of scale and volume to writeoff R&D costs for Cell and Cell2. The design goals for CPUs in game consoles and Media consoles is similar enough that the CPU can be used for both. For this reason alone I'm not concerned that Sony will drop out, On the other hand if Sony is more media oriented they might not be concerned at a later launch if it meets the roadmap for the big picture Sony.