AMD Ryzen AM4 RAM Timings Help Plz

pete_agreatguy · 1 Jan 2019 at 15:13

Hi all,

m/b = Asus Prime B350M-K

RAM (memory) = 1x 8GB Crucial Ballistix Sport LT (BLS8G4D26BFSE = DDR4-2666MHz, CL16-16-18-18 @ 1.2v)

I understand that the timings are relating to the CL-tRCD-tRP-tRAS in the product flyer (page 2)?

In the BIOS I have understood the following so far but I need clarification on the tRP and tRAS settings please:

DRAM CAS# Latency = CL, so set as 16
Trcdrd = tRCD read, so set as 16
Trcdwr = tRCD write, so set as 16
DRAM RAS# PRE Time = tRP??? so set as 18
DRAM RAS# ACT Time = tRAS??? so set as 18

Am I understanding this correctly?

Thank you

SEE THIS POST FOR FINAL TIMINGS AND FINAL SETTINGS !

pete_agreatguy · 1 Jan 2019 at 16:47

Just want to use the crucial settings. Does xmp set these as crucial overclocked settings?

pete_agreatguy · 1 Jan 2019 at 19:52

Hi, I've been reading up on it. XMP seems to be an Intel setting.

Asus have D.O.C.P instead which reads the Intel timings and does some kind of conversion (as in that calculator you linked me to) - btw not that great ... it was recommending 1.32v with 12-15-15-15-30-48 (CL-tRCDwr-tRCDrd-tRP-tRAS-tRC).

Apparently all I need to do is set the following in the BIOS:

Ai Overclock Tuner = D.O.C.P
D.O.C.P = D.O.C.P. DDR4-2666MHz 16-16-18-18-1.2v
Memory Frequency = 2666MHz
DRAM voltage = Leave as AUTO ??????? Set as 1.2v / 1.35v ?????

Assuming that D.O.C.P. setting selection is correct? Please correct me I am wrong :/

What do I need to set voltage as ????

EDIT: And do I need to change the timings manually? Assuming no?

pete_agreatguy · 1 Jan 2019 at 20:15

Hi,

I had already read that post

Hence why I was asking for clarification on the DOCP and Voltage settings only

Ai Overclock Tuner = D.O.C.P
D.O.C.P = D.O.C.P. DDR4-2666MHz 16-16-18-18-1.2v (assuming this is correct?)
Memory Frequency = 2666MHz
DRAM voltage = n/m answered above now

pete_agreatguy · 2 Jan 2019 at 12:05

I got Crucial to send me the data sheet which listed the CL-tRCD-tRP (16-18-18) but not the tRAS. After searching many google results, I managed to find out that the tRAS is 38 from a Russian e-retailer (won't link)

So I now know the proper timings lol. Me and the Crucial tech support chat person were utterly shocked they didn't include the tRAS in the data sheet.

Final Timings for the 8GB (BLS8G4D26BFSE) are: 16-18-18-38 (CL - tRCD - tRP - tRAS) @ 1.2V
NOTE: To be confirmed by higher end tech support in Crucial yet via email ...

Just in case others stumble across this thread; module markings with 240 (i.e. not 26B) are different: 16-16-16-38.

Therefore I will need a DOCP profile of DDR4-2666MHz 16-18-18-38-1.2v

Many thanks for all your help all. I'm not building this, just aiding someone else lol.