Power Management
DRAM operated at high temperature may require shorter refresh intervals. Which pairs the reason with the effect on power correctly?
- AAt high temperature cell charge increases, so refreshes and power decrease
- BTemperature and refresh interval are unrelated
- CAt high temperature cell leakage rises and charge is lost faster, so refreshes increase and so does power
Show answer and explanation
Answer: C. At high temperature cell leakage rises and charge is lost faster, so refreshes increase and so does power
DRAM cells hold information as charge on capacitors, and rising temperature increases leakage so charge drains faster. To avoid losing data, refresh must occur more often, and many standards halve the refresh interval in the high-temperature range. Refresh power rises accordingly, and so does the time the DRAM is unavailable during refresh, so cooling also affects DRAM power and performance.
- A. Charge is lost faster, not gained.
- B. It depends strongly on temperature.
- C. Correct. Standards commonly double the refresh rate above 85°C.