Just found out that on RocketLake CPU, *_dd and *_dr is reversed compared to CometLake.
Since I'm running only 1 stick of RAM per channel, I should be able to drop *_dr = 0

Getting pretty much similar AIDA number compared to previously when *_dd == *_dr ... noticed latency drop just a little bit, perhaps placebo effect

the ram can squeeze about another 1-5% wan... even in a gpu bottleneck situation. That's why it is quite significant, especially those competitive 3dmark port royal guys.

LOL... if I want absolute bandwidth, then I should switch back to my previous Hynix DJR   -- almost able to achieve 4800MHz.  If I spend more time tweak it, should be doable.

Anyway, on B-die, I'm able to get 4266 17-17-17-37 @ 1.5V stable, passing few rounds of TM5 and also GSAT.  The trick is to enable DIMM ODT training to find the best RTT_* value.  After that, disable DIMM ODT training and manually fix the value so it doesn't change.

Only 1 small problem remain... upon cold boot when temperature is around 30C, will fail memtest.  Need to warm up the RAM first before everything passing.  So, I guess I need to reduce the tREFI, cannot use the max value.

Hmm... I’m consistently getting error with RTT_WR/PARK/NOM = 80/48/40. This is stock.
Once changed to 120/48/40, no more error. Got this value after enabling ODT training.
Strange thing is that only ChannelA change RTT_WR=120.
Perhaps my RAM is not perfectly identical.

Here's my current stable config:



With both RTL training and ODT training enabled.
May I know which timing is whack?

Will try your suggestion later.
My actual goal is to boot 4533 with this kit.  So far always fail training - stuck at postcode 55.

Hmm... this is what I have:



Care to tell which timing is out of place?

Finally able to make 4400 17-17-17-37 @ 1.5V stable.
Did a couple of things:
1) Swapped the DIMM.  After the swap, I can use default RTT_* 80/48/40 without error on 4266.
2) Bumped speed to 4400 and reduce tREFI to 32768... just some numbers that I pick.
3) Attached a small fan to blow at the DIMM to reduce the temperature.

Not sure if I'm following exactly your suggested timing but here it goes:



Looking stable and seeing some boost in read speed.

Tried that and failed to boot up, postcode stuck at 5d.
Hmm... looks like raising trefi to max is the one failing.