Call me surprised when I found the new memory settings under the 1702 bios that was just released. The ones that are especially interesting are the fail retry which asus was a bit late to the party to get included even in the z490 boards, x570 now has it as well so why not z390.
https://i.imgur.com/0Cq5I56.png Next is the skip refresh which brings into new rules when it comes to trefi and temperature management, if you are going to run this might I suggest lowering vppddr, I found 2.1 to be still stable with my 4x4200 b die oc.
https://i.imgur.com/2pM9Rb3.pngFinally I want to bring up the elephant in the room, its a setting called PPD, precharge power down, if you haven't found this setting within memtweakit (and have broken enough windows for memtweakit to still even work.
What I would like to ask of Asus is to have PPD added to the next z390 bios, I feel if other settings have been back ported why not this. We cannot use memtweakit in its current form with windows 2004 updated and certainly not with 2009 upcoming with the lovely kernel security update baked in.
I ask kindly of you not to bar off a small portion of your very active userbase in favor of just the new models, there is a team working on the bios and this request has been made by the community to be bought to z490, is this deemed to become a z490 only tweak, Precharge power down, which brings my latency on 4 dimms to a shocking 33ns with my 9900k.
Please Asus and thank you for your time, a valued and extensive ROG fanatic