1 and 3 ram slots are physically closer, why does 2 and 4 offer a bit more performance?

[adarw]

title says it all, 1 and 3 are physically closer yet 2 and 4 are faster, why? 

 

 

thanks!

 

adarw

[aDoomGuy]

I think the traces still have equal distance and 2 and 4 gives more compatibility with big air coolers if only 2 slots are occupied?

[GuiltySpark_]

2 and 4 are not faster.

 

In order to take advantage of dual channel, you need to use alternating slots. In the below image, A1 and B1 need to be populated for dual channel, as would A2 and B2. Theoretically it shouldn't matter if you choose A1 and B1 or A2 and B2 but some boards manufactures, likely for minor reasons like trace length, cooling or CPU cooler clearance reasons suggest A2 and B2 if you're only using 2 modules. 

 

[adarw]

22 minutes ago, rickeo said:

 

In order to take advantage of dual channel, you need to use alternating slots

about that, is this needed for motherboards to be made like that or is it just because they wanted to?

[Zagna]

Most often the memory channels are wired such that channel #1 first goes to slot #1 and then slot #2. Channel #2 goes slot #3 -> slot #4.

So if you put memory in slots 1/3, the traces from slots 2/4 introduce very minor electrical interference from not being terminated.

Put it in slots 2/4 and the traces end at the memory modules and terminate. It's easier for the memory controller.

[Guest]

1 hour ago, adarw said:

title says it all, 1 and 3 are physically closer yet 2 and 4 are faster, why? 

 

 

thanks!

 

adarw

It's nothing other than design choice.

 

Because of bios and electrical design, memory compatibility should simply follow the manuals instructions. Per the proper slots.

 

So no, just because the first slot is closest doesn't mean it's fastest. It's simply not designed this way. 

 

Boards that lean towards memory performance will be fitted with only 2 slots, when occupying 4 slots, this typically reduces performance running a lower frequency to accommodate the increased capacity.

 

At this point, Asus Apex would be ideal, has 2 slots and completely geared towards memory OC. But that's by design choice. Most other boards can just about accomplish the same thing having 4 slots, just populate 2 and off you go.

 

But more to memory overclocking than just simply slot orientation. It really won't matter if you're running LPX 3000 sticks cause you'll probably never see past 4000 if your lucky to get that far.

 

So for 99% or more of the people out there, the slot orientation just really doesn't matter honestly.

[adarw]

10 minutes ago, ShrimpBrime said:

It's nothing other than design choice.

 

Because of bios and electrical design, memory compatibility should simply follow the manuals instructions. Per the proper slots.

 

So no, just because the first slot is closest doesn't mean it's fastest. It's simply not designed this way. 

 

Boards that lean towards memory performance will be fitted with only 2 slots, when occupying 4 slots, this typically reduces performance running a lower frequency to accommodate the increased capacity.

 

At this point, Asus Apex would be ideal, has 2 slots and completely geared towards memory OC. But that's by design choice. Most other boards can just about accomplish the same thing having 4 slots, just populate 2 and off you go.

 

But more to memory overclocking than just simply slot orientation. It really won't matter if you're running LPX 3000 sticks cause you'll probably never see past 4000 if your lucky to get that far.

 

So for 99% or more of the people out there, the slot orientation just really doesn't matter honestly.

that actually makes sense, i have another question, so exactly why is dual chanel faster than just single channel? 

[Kisai]

1 hour ago, adarw said:

title says it all, 1 and 3 are physically closer yet 2 and 4 are faster, why? 

 

 

thanks!

 

adarw

Because there's two channels, so each "pair" belongs to one channel, and that's how the traces line up.

 

[BiotechBen]

If you were to measure the signalling time in picoseconds or femtoseconds you might see a difference between the 1/3 and 2/4 slots, but you would need an atomic clock to be able to even detect it, let alone measure it.

[Guest]

6 hours ago, adarw said:

that actually makes sense, i have another question, so exactly why is dual chanel faster than just single channel? 

Essentially the cpu can read and write off two sticks simultaneously as long as they are in sperate channels. Thus triple and quad channel is faster than dual.

[Beerzerker]

Just be aware there are a few boards out there (Probrably nothing currently sold today) that have their channels right beside each other instead of alternating slots across the board.
MSI has made some that way before but the good thing is they are clearly marked (Colored) so you know about it when you look. Have one like that here and the black sots are the two closest to the chip, the blue slots are the outer ones. (MSI 870A-G54).