Processors

[irakandjii]

Is there an official "engineering" resource to assist in understanding DDR5 memory selection and deployment on AM5 boards?

I am looking for real engineering data, not marketing, or the speculative and unreferenced opinion  I constantly see on youtube or redit.

Specifically:

What are the engineering ramifications of slotting memory?

• 1DPC single rank, 2DPC dual rank etc.  I see the "bandwidth" specification in the mother board documentation for Tps impacts but no discussion on reliability etc.
• Lots of folks (internet search),  with no engineering credentials,  stating the 2 sticks of dual rank is better than 4 sticks of single rank. or even  "AMD does not work with 4 sticks" <- Clearly false

So what are the real impacts of 2 vs 4 sticks on AM5?  Historically there is an impact of having unterminated traces in a daisy chain which suggests, on that basis, 4 is better for example.

[elstaci]

This tech site seem to have technical data on DDR5: https://www.researchgate.net/publication/336739697_DDR5_Fifth-generation_of_DDR_Memory_Module

Also this tech site explains some information concerning DIMM Slots: https://www.rambus.com/blogs/get-ready-for-ddr5-dimm-chipsets/

[irakandjii]

Thank you

[irakandjii]

I read these and they represent some of the better information out there.  They are however, old being pre-release and not engineering grade.

I did find a you tube where a fellow used a brute force method of testing to show that 2 sticks of DDR 5 dual rank is faster than 4, the assumption it is the onboard memory controller.

I cannot find and rational why "AMD has a bad memory controller and can't handle 4 sticks" a popular belief on the net.  In the absence of engineering specs, I guess this will have to do.

[Jxdking]

I can do 6400mhz on 2x32gb Hynix kit with 7950x. Let me know if anyone can manage that with 4x16gb.