DDR4 Dual Channel ? ? ?

[HC1Gunner]

Its been awhile since I've built a new PC. I'm either installing a total 32GB or 64GB of RAM. If my memory serves me right, Dual Channel uses the first (2) dimm slots. Meaning that if you're running a total of 32GB, your system will see better performance if you buy a memory kit that is (2) sticks of 16GB, verses buying a kit that is (4) sticks of 8GB, as only the first two dimm slots are "dual channel".
Am I correct in my thoughts?

 

[xman2007]

Its been awhile since I've built a new PC. I'm either installing a total 32GB or 64GB of RAM. If my memory serves me right, Dual Channel uses the first (2) dimm slots. Meaning that if you're running a total of 32GB, your system will see better performance if you buy a memory kit that is (2) sticks of 16GB, verses buying a kit that is (4) sticks of 8GB, as only the first two dimm slots are "dual channel".
Am I correct in my thoughts?

If you buy 4 matching sticks they will all be in dual channel mode. 2 sticks depends on the motherboard it's not always the first 2 slots, sometimes it can be slot 1/3 2/4 etc depends on the particular board in that case

 

[OneMoar]

most boards these days skip a slot x M x M or M x M x
where m=memory consult your board manual for the proper dual channel config
and no in quad stick configs two sticks share a channel, that being said its generally accepted that two sticks are better then 4 not only for future expansion but its easier on the imc which can be a factor at higher frequencys (>3866)

 

[AsRock]

Yes better get the manual out for best confiig these days.

 

[ThrashZone]

Hi,
No need to worry about slot orientation for dual channel until you get a board, as said they are different and the web pdf or paper manual will clear that up
I would download in advance the boards pdf to get info on it I was thinking of buying.

 

[HC1Gunner]

New boards uses the 2nd (A2) and 4th (B2) slots for dual channel with (2) sticks.

 

[SomeOne99h]

New boards uses the 2nd (A2) and 4th (B2) slots for dual channel with (2) sticks.

Don't just put a general rule for that. Just check the manual for each motherboard you buy as TPU fellas recommend.

 

[HC1Gunner]

Let me straighten part of this out, I'm a retired IT professional who has built tons of PC since 1988. As soon as I knew what board I was purchasing, the very first thing I did was download the its manual, that's why I posted the slots as I did, it was not made-up / generic. Electronics are changing (advancing) all the time with motherboards, the rule use to be, to have dual channel, it only worked with using two of the four dim slots. If you placed the same memory type in the remaining two slots, you would add to the total of overall memory, but the last (2) sticks added, do not run as "dual channel". And those last (2) sticks not get used until you run out of memory with the (2) sticks running under dual channel. For all I know, board architecture could have advanced where you have have all four dimm slots filled, with all (4) sticks running as dual channel.

 

[biffzinker]

For all I know, board architecture could have advanced where you have have all four dimm slots filled, with all (4) sticks running as dual channel.

All the recent boards I've had suggest populating the 2nd slot for one stick, and 4th slot with a kit for dual channel.
From the MSI B450 Tomahawk manual:

 

[OneMoar]

most boards are color coded with the primary color being your two stick dual channel config
the reason for skipping a slot is that puts the ram sticks at the end of the buss where there is the least noise as well as depending on how the board is wired and what platform you are using
some-boards will not boot if you don't use the correct slots or if they do it may not run at the rated speed or have the full capacity


this is also partly the reason you can get higher memory frequency with two sticks vs 4

I don't know why this thread is going on and on just consult the manual and you will be fine

 

[biffzinker]

the reason for skipping a slot is that puts the ram sticks at the end of the buss where there is the least noise

I didn't know that, thank you.

 

[HC1Gunner]

Colored dimm slots seem to disappear awhile ago, most boards, especially gaming or enthusiast broads, the slots are all black now. What OneMoar said is correct, most boards will not post if two sticks are installed incorrectly.
I did look at the manual, read my reply. The manual shows where (2) sticks need to be placed for dual channel. But then also makes it appear that if you buy a (4) stick memory kit, you get dual channel benefits across "all four" sticks. In the past I have never seen any board support dual channel on all for slots.

 

[OneMoar]

with four sticks all its doing is interleaving and while boards don't make a point of it every board I have ever seen has dual channel in a quad stick config unless you are talking 10 years ago
but I would just get two 8GB 3600Mz sticks and call it a day

 

[ThrashZone]

Hi,
Daisy chain verses topology mother boards

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[newtekie1]

I did look at the manual, read my reply. The manual shows where (2) sticks need to be placed for dual channel. But then also makes it appear that if you buy a (4) stick memory kit, you get dual channel benefits across "all four" sticks. In the past I have never seen any board support dual channel on all for slots.

All recent boards work with dual-channel on all 4 slots. Since at least the 775 days, 4 sticks work in dual-channel.