'Mirrorbit'/'Strataflash' for DRAM?

[Mark R]

It's been common for a number of years for flash memory to store 2 bits per transistor - with some groups working on 3 bits.

However, DRAM is still firmly 1 bit per transistor, and is significantly more expensive than flash.

Is there any chance that multi-bit techniques could be applied to DRAMs in an attempt to increase capacities/decrease costs?

 

[CTho9305]

To do something like strataflash, you'd have to have multiple voltages stored on the capacitor. You'd have to refresh the capacitor more often, since you'd have less margin between the possible states (assuming you can even detect the "clean" states properly - I think DRAMs are sensed and have low-swing bitlines already). I don't know enough about Mirrorbit to understand how it would apply at all to DRAM.