Setting the Memory Refresh Rate

Principles

The DRAM uses a capacitor to store data. Due to electric leakage of the capacitor, charges are discharged after a period of time. As a result, the data cannot be stored for a long time. Therefore, continuous charging is required. This action is called refresh. The memory is automatically refreshed by line. Memory refresh degrades memory performance and is therefore not executed when data is being read or written. In addition, the discharge rate increases as the temperature increases. According to the component manual, when the chip surface temperature ranges from 0°C to 85°C, the memory data needs to be refreshed every 64 ms. When the temperature ranges from 85°C to 95°C, the memory data needs to be refreshed every 32 ms.

The BIOS provides the auto option for setting the memory refresh rate so that the memory refresh rate can be automatically adjusted based on the operating temperature. Compared with the default 32 ms configuration, the auto option improves memory performance and ensures memory data reliability when the operating temperature ranges from 85°C to 95°C.

Modification Method

Access the BIOS page based on Accessing the BIOS, and then set the memory refresh rate, as shown in the following figures: