4 ms·
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,
by codebook 11y 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.
- witty_username 11y agowatt per second makes little sense in this context watt != energy
- dooptroop 11y agoBut Watt * second IS energy.
- mmf 11y agoIt'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.
- witty_username 11y agoAh, it made sense now.
- mmf 11y agoA 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.