Originally Posted by pyromaniac1
Hmmm thanks guys. This is very interesting.
I have a pair of b-die Adata XPG d41 AX4U360038G17-ST41 which is 17-18-18-38, and I've run it on 3 boards (Gigabyte B450 Aorus M, Asrock B350m pro 4 and Asus X370 prime pro), and I've not been able to get it past 3266 stable. This is across a 2600 and a 2600x.
So I guess I'll hold off on selling the prime pro off in favor of some x470 board for a higher price. If It doesn't let me get higher mem clocks it'd be a pointless purchase.
All B die is not the same, so you may see someone clock better or worse. But what creates the bigger disparity is IMC quality and some what UEFI options/development.
I've had 2700X 1835 PGS ~1.5weeks, I've experienced/had C6H/C7H/ZE with Ryzen gen 1/2 and Threadripper since launch. At times I've used same ram kits between each.
C6H + Ryzen gen 1 originally 3200MHz was a push at launch for me. Slowly as AGESA/UEFI developed 3466MHz was stable/sound for daily use. ZE+TR from launch 3200MHz was easily had, few months later 3466MHz for me. C7H + Ryzen gen 2 3466MHz was easily had at launch, now on my 3rd CPU and nabbed 3533MHz C15 1T at SOC 1.025V VDIMM 1.35V. Latest UEFI released few days ago nabbed 3600MHz C15 1T.
The RAM sticks used above, used to top out at 3466MHz on C6H + gen 1 or ZE + TR gen 1, usually needed more than 1.35V. Same do 3533MHz with 1.35V on C7H + gen 2 and as shown above 3600MHz at 1.385V.
At times I know I given upto 1.4V to claim 3466MHz stability on the older setups. The reason I believe it was needed was weaker IMC. Elmor shared OC guide in C6H thread, in there you see a note where VDIMM limit is considered from IMC side. So IMO VDIMM requirement is not just based on RAM IC, but also RAM IMC, it must have something to do with the link between each IMO. Thus I see same RAM clock higher at lower VDIMM than other setups I've had in my hands.