Crosshair VIII Impact Overclock RAM D.O.C.P 2666 to 3200 or 3600 MHz

[user_x]

Hello, hope all of you are doing great. I need some help with the motherboard settings for memory overclock. Here is the spec:

• ROG Crosshair VIII Impact
• BIOS 4805 - 18 March 2024
• AMD Ryzen 9 5950x
• 64 GB DDR4 RAM - 2 x 32 GB 
• Air cooling

Memory details 2 DIMM slots (A1 and B1) each having Crucial memory:

• part number BL32G36C16U4B.M16FB1
• speed 2666 MHz
• size 32 GB

So here is there story. I built this PC a couple of years ago and as I remember it took me a few tries of changing various settings, I think SOC 1.05V and DRAM 1.4V voltage but I am not 100% sure, eventually I managed to have it running stable at 3200 MHz (if I remember correctly). 

Recently I have upgraded the BIOS and unfortunately I forgot to backup the settings on USB (I had only the internal one in the BIOS and I didn't realise they will be wiped... lesson learned). So I now do not remember exactly what I did before to overclock the RAM.

Also, the DOCP has 1 option of 3600 MHz, but when I set that I get the black screen, and then I have to reset the system using the button at the back. 

Does anyone of the more experienced members in this forum know what are the settings I need to tweak, and what are the typical safe values? Is it just the 2 voltages or do I need to change something else as well, perhaps the timings? 

Also, do I have any chance to get the 3600 MHz working or am I wasting my time and better stick to 3200 which I had working before? and if yes, would I have more chances going for 3600 with the preset DOCP option or on Manual?

System is also undervolted with different values per core if that matters, thankfully I had those numbers saved so I managed to manually recreate them.

Let me know if you need more info. I will update here with my findings when I try a few solutions,

Thanks in advance!

[hankieroseman]

Look up AMD EXPO. Supported in the BIOS newest V.4902

[user_x]

Thanks this looks like exactly what I need but unfortunately doesn't seem to be available for socket AM4 which is mine. Looks like it needs AM5. 

I did try some combinations yesterday, I found some useful manual on github, though a bit out of date but barely covers my CPU model. Managed to get into windows with 3600 MHz but very unstable, crashed immediately on the very basic of memory tests... I will try again today from scratch, probably some setting I missed. I will report back here as I make progress

[hankieroseman]

It's the BIOS I saw for your Hero Impact MoBo. Same as my HeroVIII.

[user_x]

I managed to do this 3600 and undervolting, took a few tries, I will post more later, also could upload the file with all settings if anyone interested. What's the best way to include my config here? can I attach it? or post a link to it? or add it to this post (it will be a long text). Can any of the site admins tell me what's the best way to do this in order to help others?