ram, overclocking and ranks

[notalearnedman]

Hey so i was thinking with ryzen cpus, whats an ideal setup for some light overclocking with ram. 4 ranks with 2x16gb or 4 ranks with 4x8gb? So you would be getting 32gb total.

 

Now ive heard that duel rank ram can be harder to overclock compared to single but ive also heard that memory controller is strained more on ryzen cpus with all dimm slots filled, so in theory would that make 2x16gb better to use? EVEN though its using the same amount of ranks? doesnt that make it exactly the same for the memory controller? I dont understand how the channels with have an impact since in either case your running 4 ranks on both channels.

This is one part of the ram overclocking im having trouble wrapping my head around.

 

edit: i should probably mention im mostly asking about daisy chain mobos

[Senzelian]

I wonder what you mean with ranks, because a DIMM is either available in either single rank (SR) or dual rank (DR).

 

Do you mean two DR DIMMs vs. four SR DIMMs?

[Jurrunio]

Less sticks is better, even for T topology boards.

[notalearnedman]

12 minutes ago, Senzelian said:

I wonder what you mean with ranks, because a DIMM is either available in either single rank (SR) or dual rank (DR).

 

Do you mean two DR DIMMs vs. four SR DIMMs?

Sorry think i explained that badly. Yeh thats pretty much what i mean, now im not a learned man, but to my knowledge most consumer 16gb sticks are duel rank (8+8), while most 8gb sticks are single rank (+8) so yeh why would less sticks, in this case 2x16gb be better over 4x8gb?

[Senzelian]

8 hours ago, notalearnedman said:

Sorry think i explained that badly. Yeh thats pretty much what i mean, now im not a learned man, but to my knowledge most consumer 16gb sticks are duel rank (8+8), while most 8gb sticks are single rank (+8) so yeh why would less sticks, in this case 2x16gb be better over 4x8gb?

Roughly a year ago I looked into single rank and dual rank memory myself and I found that apperantly dual rank DIMMs generally perform better than single rank DIMMs on Ryzen platforms, which would defeat the purpose of overclocking single rank memory. Now, I haven't seen any new data yet, so that's something you'd have to look into yourself.

 

But as @Jurrunio pointed out, less sticks are better, even tho I have no clue what T-topology boards are.

Can you explain that further please?

[Jurrunio]

3 hours ago, Senzelian said:

I have no clue what T-topology boards are.

Can you explain that further please?

The traces goes to the middle of two sticks, then splits into 2 into the memory slots so all slots in the same channel get equal trace length.

[notalearnedman]

10 minutes ago, Jurrunio said:

The traces goes to the middle of two sticks, then splits into 2 into the memory slots so all slots in the same channel get equal trace length.

Ok so I guess that’s why there’s a lessened drop off in clock speed when using 4x8 in t-topology when compared to daisy chain?

 

so the traces are the reason why duel rank with less slots (2x16) gives you a better experience than 4x8 on daisy chain boards. Is that correct?

[Jurrunio]

18 minutes ago, notalearnedman said:

Ok so I guess that’s why there’s a lessened drop off in clock speed when using 4x8 in t-topology when compared to daisy chain?

 

so the traces are the reason why duel rank with less slots (2x16) gives you a better experience than 4x8 on daisy chain boards. Is that correct?

Yes

 

Yes on some platforms. Some other memory controllers may be tuned so well they dont need T top to do ok with 2 sticks per channel (and T top does nothing but reduce 1 stick per channel)