DIMM and Dual-channel memory

hamada.hosny93

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Apr 23, 2018
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Hi guys, actually i'm little low experience about some stuff in the content of motherboards like DIMM and dual-channel memory so i need some help to get some knowledge about them.

Well. first of all when i read some overview about a motherboard it says (for example ) it has 2 DIMM supporting up to 32-GB of system memory ... until this moment i understood that the maximum memory of ram that the motherboard supports is 32GB

So what does "DIMM" means??
and how many memory slots will be available to use?
by other means: How many sticks of ram can i install in the motherboard?

also what does dual-channel memory means? and if i used that capability how many memory slots will be reserved from the total memory slots of the motherboard?

Thanks in advance :)
 
Solution
Dimm is desktop sized ram. So that means it has 2 slots so 2 sticks can be used. Sodimm is laptop size ram. There are some desktop mobos with laptop ram slots. These are typically the small form factor mobos.

Dual channel is like using a 2 line road to get to the ram while single channel would be a 1 lane road. More data can be simultaneously transferred to and from ram. This would be double the bandwidth vs single channel. This requires at least 2 sticks of ram.

I don't know what you mean by how many are reserved. You got 2 sticks, you can use 2 sticks. If you only have 1 stick, you can only use 1 stick. There is nothing you can't use because of channeling.

Do not confuse double data rate with dual channel. These are 2 independent...
Well the short answers are as followed:

1) DIMM - Dual In-Line Memory Module.

2) Motherboards, depending on the type, can have 2 (mostly laptops only), 4, 6, or 8 DIMM slots for memory.

3) Memory capacity is set by the motherboard vendor and there's a limit to the size of individual memory modules they can take. So for example if you have an older Sandy Bridget P67 motherboard and it supports up to a max 4GB individual DIMM slot memory modules with a max capacity of 16GB, with four slots you won't be able to get more than 16GB in there vs. trying to upgrade with four 8GB modules for 32GB.

4) DDR memory means "double data rate" and it relates back to #1. In basic layman's terms, DDR memory of any type works best when running in dual channel mode pairs vs. single channel for maximum throughput and performance.
 
Dimm is desktop sized ram. So that means it has 2 slots so 2 sticks can be used. Sodimm is laptop size ram. There are some desktop mobos with laptop ram slots. These are typically the small form factor mobos.

Dual channel is like using a 2 line road to get to the ram while single channel would be a 1 lane road. More data can be simultaneously transferred to and from ram. This would be double the bandwidth vs single channel. This requires at least 2 sticks of ram.

I don't know what you mean by how many are reserved. You got 2 sticks, you can use 2 sticks. If you only have 1 stick, you can only use 1 stick. There is nothing you can't use because of channeling.

Do not confuse double data rate with dual channel. These are 2 independent specs. DDR has nothing to do with DIMM. There are also SDR DIMM. DDR has nothing to do with the number of channels. All desktop ram is DDR hence the name and DDR1, 2, 3, 4 are just the versions. Not all mobos are dual channel so not all work best with pairs. There are also mobos with 1 and 3 slots, not just 2, 4, 6, 8. There are also more than that but not consumer level. The 3 and 6 slot mobos are tri channel, 8 slot is quad channel. Because of how multi channeling works, there are 2 sticks max per channel. Max memory capacity tends to be the max when the mobo was made, not the max it supports. They just don't update the spec sheets because they don't test them. Many older mobos like p67, are fully capable of 8 and 16gb sticks.
 
Solution


Thank you so much bro for that info, but let me ask you 1 more question again to get the full understanding in my mind:

As you said "DIMM" means Dual In-Line Memory Module, lets take the h310 motherboard as a guide for my new question because maybe i will buy it very soon.

Well, h310 motherboard contain 2 DIMM supporting up to 32-GB of system memory with dual channel ... so my question is: "is that means i can install 2 memory sticks in 1 single line (1 DIMM) ??" ( for example 2x8GB) ... so by this way i can benefit from the capability of dual-channel ??
 
Yeah I was just using that P67 example as a hypothetical on limits of what motherboards can accept. In any event I'm not sure I understand the question about installing "2 memory sticks in 1 single line (1 DIMM) ??" (for example 2x8GB)" there. As k114 said above, you can run any combination of modules up to the max allowable individual DIMM slot size. So that means even being able to use three modules in a motherboard with four slots. However, in that case, only those first two memory modules will be able to run dual channel configured. That third module will be single channel. Think matched channels be it 2x, 4x, 6x, etc. for taking advantage of multiple channels on memory *if* supported.

This is where you need to do your homework and research the motherboard specs and capabilities. Before I buy a motherboard I'm looking at, I'll go to the product page of it and download the user manual just to ensure it fully supports my needs. Product descriptions on seller sites like say Amazon and NewEgg may not list complete spec details that may be an important factor for you.
 


I appreciate all the info you provided to me about this topic, but unfortunately i still can't find the exact answer that i was waiting for so let me try to clarify more:

Consider the h310 motherboard as our guide, it has 2 DIMM, is that means that it is only has 2 memory sticks i can install ? or by other means: there is no way to get the full 32-GB of system memory except installing 2 sticks of ram (1 stick = 16-GB) ?? also there is no way to get benefit from using dual-channel capability except for using (2x16GB ram) if i wanted to get the full 32-GB at the same time??

My regards :)
 


My apologies man, i didn't miss your post but actually got confused by some info included but now i fully understood everything, thanks to you so so much :) :)