Can you show a pic how it look in Polaris editor? Open a fresh bios file without any changes.
Top right should have a drop down which shows memory types. By this you can figure which strap lines to edit for that memory. It is possible bios has 1 mem type. Although rare but possible. Other have 3 mem types like mine 570s. Etc.
Get the very latest polaris editor github.com/jaschaknack.
Best bios is your bios

For elpida this should work . For above 1500 straps use below. no need to change anything else except use the strap on mem slots 1500 and above.
777000000000000022AA1C00315A5436A0550F15B68C1506004082007C041420CA8980A9020004C
01712262B612B3715
For over clock try initially core 1150 mem 1950 from Windows tool like msi afterburner or other.