Secondary RAM slots not really working?

[Tan3l6]

Specs:

Spoiler

So the secondary slots (DIMM_A1 and DIMB1) are not really working - motherboard or CPU issue?

Spoiler

Once I had the patience to wait with 4 DIMMs in auto speeds and the 4 sticks booted at 3600MT/s...

but at 6000MT/s with the secondary slots only DIMM_A1 and DIMM_B1 populated won't run at 6000MT/s.

 

What could be the issue? RAM, CPU or motherboard?

[Millios]

28 minutes ago, Tan3l6 said:

Specs:

  Reveal hidden contents

So the secondary slots (DIMM_A1 and DIMB1) are not really working - motherboard or CPU issue?

  Reveal hidden contents

Once I had the patience to wait with 4 DIMMs in auto speeds and the 4 sticks booted at 3600MT/s...

but at 6000MT/s with the secondary slots only DIMM_A1 and DIMM_B1 populated won't run at 6000MT/s.

 

What could be the issue? RAM, CPU or motherboard?

If i remember correctly the manuals say to populate specifically A2 and B2 (at least first) for that reason (stability) based on their topology (vid is a few years old but it'll give you the gist of it)

TL DR its an "issue" thats based on motherboards

 

For 4 sticks its just an issue with the memory controller on the CPU where 4 sticks high speed is just smt it cant handle (most of the time at least)

[Tan3l6]

4 minutes ago, Millios said:

If i remember correctly the manuals say to populate specifically A2 and B2 (at least first) for that reason (stability) based on their topology (vid is a few years old but it'll give you the gist of it)

TL DR its an "issue" thats based on motherboards

 

For 4 sticks its just an issue with the memory controller on the CPU where 4 sticks high speed is just smt it cant handle (most of the time at least)

I guess there's nothing to do about it other than run 4 DDR5 sticks at 3600 or 2 sticks at 6000+MT/s?

[Millios]

Just now, Tan3l6 said:

I guess there's nothing to do about it other than run 4 DDR5 sticks at 3600 or 2 sticks at 6000+MT/s?

It should be able to do a lil higher at 4 sticks. 5200mhz is common from what I've seen and 5600mhz is ok if you won the silicon lottery like with 6400mhz at 2 sticks

I would opt for higher capacity at 2 sticks tho cause it gives you the ability to run it faster

Tho how much ram is it? Cause if I remember correctly after a certain amount (smt like over 128GB, i cant recall the exact number) its also too much for consumer CPUs so they run into stability issues as well

[Tan3l6]

Just now, Millios said:

Tho how much ram is it? Cause if I remember correctly after a certain amount (smt like over 128GB, i cant recall the exact number) its also too much for consumer CPUs so they run into stability issues as well

I tried 4x16GB same model RAM with no success at 6000MT/s 

And also the 2x16GB won't run at 6000MT/s in A1 & B1

[Millios]

Just now, Tan3l6 said:

I tried 4x16GB same model RAM with no success at 6000MT/s

Thats to be expected on AM5 which you are on with a 9800x3D (btw I dont mean it in a patrionising way I just like to make full statements in case I got a detail wrong and smb catches to correct me)

 

2 minutes ago, Tan3l6 said:

And also the 2x16GB won't run at 6000MT/s in A1 & B1

Yeah from what I can find (if it is specifically A1 and B1 and not in general the 2 matching slots) its an "issue" of the motherboard architecture and how the slots are wired

Linus did a bit on it with Shahrad (srr if I butchered the name) here

Where they made Shahrads law

And I quote (liberally) "THOU SHALL NOT PLACE YE RAM WHERE YE OR OTHERS CANNOT LAY EYES UPON THY OCCULAR TREAT"

or just place the ram where it looks more photogenic which usually is stickers looking away and 2 fartherst slots

[Tan3l6]

OK, thanks @Millios ... that's what I suspected.