DRAM will also normally hold most of its data for 1000x longer than the rated (usually 60 ms) refresh time. This has sometimes been used to recover secrets from powered down computers. The rated refresh time is chosen to give near-zero errors over years of operation, accounting for worse-case leakage from any bit, but most bits leak much less than that.
I think older systems also tended to use a fixed refresh rate, rather than refreshing more often as the DRAM temperature rises. Temperature sensors on DRAM are more common now, so systems don't have to be so conservative with the refresh intervals.
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DRAM will also normally hold most of its data for 1000x longer than the rated (usually 60 ms) refresh time. This has sometimes been used to recover secrets from powered down computers. The rated refresh time is chosen to give near-zero errors over years of operation, accounting for worse-case leakage from any bit, but most bits leak much less than that.
I think older systems also tended to use a fixed refresh rate, rather than refreshing more often as the DRAM temperature rises. Temperature sensors on DRAM are more common now, so systems don't have to be so conservative with the refresh intervals.