AMD memory tweaking

[Islam Ghunym]

I was shrinking memory timings on AMD ASUS mobo and had some questions:

 

1- there are 2 pages in the BIOS to modify timings, one under Ai Tweaker -> DRAM Timing Control and the other one is under Advanced -> AMD Overclocking -> ....

In the first page, timings are shown in ns, but on the other page under AMD Overclocking, timings are shown in Clk and input values are a mix of numbers and letters. I chose the second page under AMD Overclocking and tried to set timings in Clks untill I reached tRDRS/L tFAW. tRDRS/L was fine at extreme tight 4 4 clks, but I had a hard time with tFAW until it never became stable at any value. It took days of trying any value under 37 and any of these lower values shows an error after 400% to near 1200% in memtest.

Last value I tried was "25" which translated as 37 ns, but that also showed an error so I reverted tFAW back to Auto which was 37! and I got no error after 2600% in memtest and looks satisfying. This means that there is actual difference between Auto value 37 and manual value "25" which is 37 ns what is it?

 

2- how should I set tRFC2 and tRFC 4.

defaults are: 312ns (512), 192 and 132 tRFC, tRFC2 and tRFC4