I have an idea...
there's a number between 128 and 256 that might just be crazy enough to work.
Im not sure whether this is possible, or whether this has been discussed earlier on this thread...
but..
I think ive come up with an idea that would solving these issues ...
1. Bandwith whilst keeping small memory controller 128bit??
2.Getting enough high density ram on board
3.keeping costs sensible
4.saving die area and expensive edram
If we think that a pool of cashe is not going to happen,
or wont suffice for the die cost..then let me propose thus...
RAMBUS XDR2 - Has twice the bandwith of even high end GDDR5.
and does it using less power....
http://www.rambus.com/us/technology/solutions/xdr2/index.html
Could that be used in say.. 1-2gb form (on die?? daughter die ala xenos??) to link the gpu, then also some sort of MEMEXPORT (ala xenos) from GPU to some high desity
/cheap Gddr3? maybe in another 2-4gb form??
In that scenario, you would get a high amount of ram, you would get very high bandwith..higher than GDDR5, less power consumption,
AND keep the memory controller small at say 128bits wide?? which would enable easy motherboard/chipset shrinkage...
As sony emcorperated some of this technique rather poorley in the ps3, and although was very expensive, managed to pull it off to some extent, i always thought that XDR memory had alot of potential..surely with 6-years gone by xdr would be available in greater density for the same price range..??
Also as GDDR5 is quite expensive, that a smaller amount of pricier XDR mated to a larger pool of cheaper gddr3 would ballance the costs for more ram and enable cost reduction techniques later on in the console life cycle.
What do you guys think...