Sony is focusing on Hard-Core Gamers for PS5

[Pemalite]

drkohler said:

Pemalite said:

Once you hit 1GB of used capacity on each chip, then you can only start filling up the 2GB chips...

And this is when you switch from clamshell mode to non-clamshell mode on the 2GByte chips on both channels, putting the 1GByte chips onto high impedance.

As you say, it is really very complicated implementing such shenanigans and I doubt they are going to implement this. 

I see either 16Gbyte on a 256bit bus or 24Gbyte on a 384bit bus, leaning towards the 16GByte solution which is obviously much cheaper. Also with the "superfast ssd" solution combined with improved memory compression technology leads me to think 16GByte will be enough memory for a console.

Microsoft's E3 trailer shows us that Scarlett is possibly using a mix of 1GB and 2GB chips.
Digital Foundry mentions it here even: https://www.eurogamer.net/articles/digitalfoundry-2019-project-scarlett-spec-analysis

Whether they employ a 256bit or 384bit bus remains to be seen... And again, I am not asserting anything as fact, just hypothesizing on possibilities.

As for the SSD... That isn't a replacement for Ram.