Question Same memory sticks, different RAS#.

[Kennusik]

Hey everyone,

I've had 2x8 CMU16GX4M2C3200C16R, which worked just fine, both XMP and DOCP (switched from Intel to AMD recently). I decided to get another pair of same RAM sticks (2x8). I received them today, installed them and noticed that although they have same number, they don't work good together.

I did memtest (without problems) and have an updated BIOS. RAM sticks are inserted properly by channels. Later I discovered that my old sticks works as dual channel, while the new ones work as single channel and got different RAS Precharge value.

https://imgur.com/7HgM4cK

Now, the problem is that when I switch to DOCP, I can't boot. Works fine without DOCP turned on. Any ideas how I might make it work?

My spec:
Asus B450-M Pro Gaming (supports only dual channel)
AMD Ryzen 5 3600

Thanks for your replies!

 

[drivinfast247]

Yup. That's normal. RAM is only guaranteed to work together when sold as a matched kit.

Try manually setting the timings. Also, you might not be able to run at 3200mhz with 4 sticks. Try 2666mhz or possibly 3000mhz.

 

[Kennusik]

Yup. That's normal. RAM is only guaranteed to work together when sold as a matched kit.

Sure, I'm just asking if there is something I can do with it, to make DOCP work.

 

[kerberos_20]

that single/dual is rank, not channel (chips on one side vs on both sides)
as for compatibility goes, old sticks are samsung, new ones are hynix
XMP will not work as both chips will need different mem training
XMP/DOCP is out of question if it doesnt boot, u will need to figure out timing on your own, u probably also need increase voltages on memory controller or ram for 4 sticks at high clocks

 

[drivinfast247]

Sure, I'm just asking if there is something I can do with it, to make DOCP work.

I added more to my post.

 

[Calvin7]

DOCP is for the memory in the form sold, not other combinations you decide to make. Of course, you can play around with DOCP, but those kind of combinations have no guarantee to work together.