I won't go into the specifics here as I've posted to other forums - however I am being told not to use the XMP profiles and instead enter in all my RAM tuning settings manually.

However, I cannot tell how this can be done in the BIOS.  While I see settings for latency, voltage, etc, I don't see a way to increase the actual clock speed of the RAM.

If I set the XMP profile from Auto to manual and select the 2666 speed then my system won't load.

If I keep the XMP on "auto" then it just detects as 2133.

How do you effectively turn XMP "disable" and manually configure all settings?

Ok thanks I did see those settings and wondered why they were a duplicate of many of the settings on the first page.

Just to confirm on the "OC Tweaker" page I should set the "OC Mode Change Switch" to "AMD CBS Setting" instead of ASRock?

"Then under Advanced\AMD CBS\UMC Common Options\DRAM Timing Options" I set the "Overclock" to "Enabled" and then fill out all the settings there?

I just tried that with a basic config and it does seem to take some effect (Ofc I'm still new to these settings so not sure exactly what to change and how it influences).

But, what I am still concerned about is that even with the configuration as above on the "OC Tweaker" page it still says list the following under my "DRAM Configuration" heading:

"XMP 2.0 Profile 1: DDR4-2666 15-15-15-35 1.20V"

Now the Auto/XMP button is no longer there "it disappears after I switched to "AMD CBS Setting" but is it normal for it to still show an XMP Profile listed there?

Thanks.  What I'm curious about the displayed profile there is that it says:

"XMP 2.0 Profile 1: DDR4-2666 15-15-15-35 1.20V"

That's whether or not I have XMP set to Auto.

But why is it showing that specific profile?

My RAM (F4-2666C15D-8GVR) is 2133 rated to 2666.

But on first system boot (no tweaks - set to Auto) the system boots 2133.

If I change from Auto to XMP 1 I can select the speed (2400/2666/etc.).

So it is saying "XMP 2.0 Profile 1: DDR4-2666 15-15-15-35 1.20V" but it is really booting at 2133.

If I actually change the profile to 2666 I have issues.

So I don't know why it is saying it using the 2666 profile when it is configured to boot at 2133.

I need to go back and test, but I think even when I set it to 2400 (which boots) it still says 2666 in that XMP profile line :?

And you may require to look for timings that would work for you at whatever speed.

Currently I am setting them by selecting the XMP profile, selecting the desired speed and changing my DRAM timings under that.

I guess my last question on this topic is how exactly is it different changing the DRAM timings under the XMP on the main page different then enabling the CBS settings and drilling down into those sub-menus to change DRAM timings?

IOW what are the advantages/disadvantages of using the ASRock OC vs the AMD CBS configuration?

thanks