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by codebook 3972 days ago
you overlooked refresh time, which is around 7~8 ms. So, in order to keep the DRAM data alive, DRAM should consume a few tenths of Watt per Gigabyte per second, it is considerable amount of power.
2 comments

A few corrections:

-refresh period is more like 32-64ms

-refreshing is way (way) cheaper than streaming data out since you refresh an entire word line, and you do not pay io cost, which is a significant fraction of the cost of accessing dram.

watt per second makes little sense in this context

watt != energy

It's W/GBps, or if you prefer simplifying J/GB. I like the former better, power and bandwidth are handier in real life computer science.
Ah, it made sense now.
But Watt * second IS energy.