Would it matter if any slot is used for a single stick ram on the mainboard?

[Mahmudul Hasan]

Hi. I am using currently MSi B450 Gaming Plus Max mainboard on my PC. Using a single stick RAM on slot 2 out f the 4 DIMM slots. I wish to know about would it matter if I use the single stick ram on slot 2 rather than slot 1 or any other? Thanks for the responses.

[Archerr]

The second and fourth slots are usually used first before the others so you should be right, but you can always check in the motherboard manual.

[boggy77]

use slot 2, as recommended in the manual

[Mahmudul Hasan]

6 minutes ago, Archerr said:

The second and fourth slots are usually used first before the others so you should be right, but you can always check in the motherboard manual.

Okay. What is the reason of using the second and fourth slots first than the others? Can you please explain?

[Archerr]

.

[Mahmudul Hasan]

3 minutes ago, Archerr said:

On most motherboard the slots numbered a1 and b1 (second and fourth) are generally accessed by the cpu before it tries to access a2 and b2 (first and third) this means the cpu will generally take less time to access the ram and provide better speeds.

wow! Understood. Let's say If I use the 2nd and 4th slot first and later I wish to use 2 more RAMs, should I put the new sticks on the slot 1 and 3?

[boggy77]

Just now, Mahmudul Hasan said:

wow! Understood. Let's say If I use the 2nd and 4th slot first and later I wish to use 2 more RAMs, should I put the new sticks on the slot 1 and 3?

yes. 2>4>1>3

[Mahmudul Hasan]

5 minutes ago, boggy77 said:

yes. 2>4>1>3

Thank you very much for the help.

[thewill102]

22 minutes ago, Archerr said:

On most motherboard the slots numbered a1 and b1 (second and fourth) are generally accessed by the cpu before it tries to access a2 and b2 (first and third) this means the cpu will generally take less time to access the ram and provide better speeds.

This is not entirely true. Most motherboards have a Daisy-Chain Topology for their RAM slots. This means that the connection for channel 1 goes from the cpu to slot 1, then to slot two. And for channel two it goes to slot 3 and then 4. If you populate slots 1 and 3, the connections to 2 and 4 are still open, so there still flows an electric current to them. Because there is nothing it connects to, the electricity "bounces" back and leads to irregularities, which can cause RAM issues.

 

So populating the slots 2 and 4, the electric signal has to travel a bit longer, BUT it ends on the RAM-Stick, leading to a clean signal and no bounce back, which, yes, leads to faster speeds, but because there are no electricity issues happening, not because the signal can get there faster.

 

LTT recently made a video explaining how a motherboard works, where this is explained too.

How Motherboards Work - Turbo Nerd Edition - YouTube

[Mahmudul Hasan]

1 hour ago, thewill102 said:

This is not entirely true. Most motherboards have a Daisy-Chain Topology for their RAM slots. This means that the connection for channel 1 goes from the cpu to slot 1, then to slot two. And for channel two it goes to slot 3 and then 4. If you populate slots 1 and 3, the connections to 2 and 4 are still open, so there still flows an electric current to them. Because there is nothing it connects to, the electricity "bounces" back and leads to irregularities, which can cause RAM issues.

 

So populating the slots 2 and 4, the electric signal has to travel a bit longer, BUT it ends on the RAM-Stick, leading to a clean signal and no bounce back, which, yes, leads to faster speeds, but because there are no electricity issues happening, not because the signal can get there faster.

 

LTT recently made a video explaining how a motherboard works, where this is explained too.

How Motherboards Work - Turbo Nerd Edition - YouTube

That is very informative. Thanks a lot.

[Nafis]

On 4/16/2021 at 3:53 PM, thewill102 said:

This is not entirely true. Most motherboards have a Daisy-Chain Topology for their RAM slots. This means that the connection for channel 1 goes from the cpu to slot 1, then to slot two. And for channel two it goes to slot 3 and then 4. If you populate slots 1 and 3, the connections to 2 and 4 are still open, so there still flows an electric current to them. Because there is nothing it connects to, the electricity "bounces" back and leads to irregularities, which can cause RAM issues.

 

So populating the slots 2 and 4, the electric signal has to travel a bit longer, BUT it ends on the RAM-Stick, leading to a clean signal and no bounce back, which, yes, leads to faster speeds, but because there are no electricity issues happening, not because the signal can get there faster.

 

LTT recently made a video explaining how a motherboard works, where this is explained too.

How Motherboards Work - Turbo Nerd Edition - YouTube

Electricity will not flow to the open slots in the first place, that explanation of electricity bouncing back defies basic electrical physics. Current simply doesn't flow to a open circuit. Unpopulated slots are marked by the motherboard and CPU during post and later the CPU specifically access the marked rams using their addresses. 

The argument could be that the CPU has the shortest path to 2 first and then 4 and then 1 to 3 subsequently through a daisy chain. The PCB layout can vary from one board to another, and board manuals usually don't even mention how is it routed.

[MrMase]

From my experience this comes down to Memory is handled between an Intel based system or an AMD based one.

 

For intel typically you would use slot 1 then slot 3 (unless motherboard manual says otherwise)

AMD it has been slot 2 then slot 4 (again unless manual says otherwise)