Doesn't matter.
The thing about phones is, you aren't performing ram intensive tasks 99% of the time.
Say you did loads of photoshop work on your computer and you also liked doing some video encoding at the same time, then you need lots of ram.
If programs/aps are properly made, without memory leaks, a phone in this decade will not need more than 512mb.
As the others have mentioned, with a partition, the dual chips are needed as different OS' are being used, so it's not that they're needed as much as they're just physically needed to run a partition.
Aka, the bionic will run fine, dual core is much more important than increasing ram at this point. It will allow you to run multiple aps, much more smoothly, as their processing power is increased, their ram needs stay the same.