I could find that there is a Refresh Period (tREF) in the memory setting, does it help?
The relevant settings are DRAM REF Cycle Time and DRAM Refresh Interval.
But I cannot recommend just changing them without a very solid testing protocol. As modifying these can easily lead to data corruption and/or increased error rates. Your motherboard executes something called a "MCH FULL CHECK" when you install new memory modules in your system and sets these values automatically based on your memory module capabilities. We select our memory modules and test them extensively for lowest overall latency and error rates while modifying these parameters. For the daring hobbyist its a way to very significantly (more then altering CAS/RAS latencies) impact overall memory access latency and power usage. But AGAIN, you can easily make things worse in stead of better, worst case being a complete operating system reinstall.