Have you ever owned a mobile device that had 1GB of DRAM? Otherwise how can you make such a comment?

I'm pretty sure that in the deep and distant past when the discussion of memory provision on earlier devices has taken place at t.m.o. (or maybe it was itt) a Nokia Tablet engineer commented that DRAM refresh power consumption is an important consideration - remember, memory has to be continuously refreshed even when the rest of the device is completely idle. I imagine the comment (which is no doubt lost in time, sadly) would apply even more so today when talking about an increase of DRAM from 256MB to 1GB.

I'd take an educated guess that 1GB of DRAM uses precisely twice as much power than would be consumed by 512MB no matter how it is "set up" (discounting the dynamic disabling of banked DRAM which is just too fanciful for words).

But hey, it's a small issue but worth knowing that increases in DRAM don't come for free.