RAM Dual-channel with different size

[3S000]

According to the Dual-channel with four DIMMs

https://www.intel.com/content/www/us/en/support/articles/000005657/boards-and-kits.html

I have some question about the size of RAM

If the DIMM 1 / DIMM 2 size for eg. 2 GB each (Both of them is the same)

• Same brand
• Same timing specifications
• Same speed (MHz)

and DIMM 3 / DIMM 4 size for eg. 4 GB each (Both of them is the same)

• Same brand
• Same timing specifications
• Same speed (MHz)

RAM in DIMM 1 /2 / 3/ 4 are the same memory channel speed.

My question is

• When installing a RAM like this in different size - Is it

create a problem when using different size of RAM ?

• When compare to 4 GB x2, Is 4GB x2 better than 4 + 2 + 4 +2 ?

Because the size in DIMM1/2 is not identical with DIMM 3,4

Thanks you.

[3S000]

Note : CPU is i5-4590 @ 3.3GHz

Window 7 Ultimate

[n_scott_pearson]

Mismatched DIMM sizes will slightly lower performance. DIMMs of same size must be in slots for ssme channel.

...S

[3S000]

Thank you for your reply. May I ask furthermore question about "ssme channel" What does it mean ?

According to the picture - If I install a RAM like this it will not be ssme channel, Am I understand correct ?

Note : A picture come from https://www.intel.com/content/www/us/en/support/articles/000005657/boards-and-kits.html

[n_scott_pearson · Accepted solution]

Yes, you are correct. That was a typo; I meant to say 'same' - but, in fact, that was incorrect.

If you follow the setup in your picture, you will achieve the highest throughput possible, namely dual-channel interleaved mode.. You want ChannelA-DIMM0 (DIMM 1 in this picture) and ChannelB-DIMM0 (DIMM 2 in this picture) to have matching size DIMMs. Similarly, for best performance, you want ChannelA-DIMM1 (DIMM 3 in this picture) and ChannelB-DIMM1 (DIMM 4 in this picture) to have matching size DIMMs.

So, to answer your original questions, no, size mismatch does not not create a problem and no, (4+2) + (4+2) will offer the same performance as 4 + 4. In fact, however, (4+2) + (4+2) will offer the better overall performance at the O/S (Windows, Linux, etc.) level simply because it makes 12GB available instead of 8GB.

I myself always like to go for the simplest solution, namely all DIMMs being the same size...😜

...S

[3S000]

Thank you very much. 😊

[bhaskar]

I want to know what will happen if I put 4GB(soldered)+ 8 GB(2nd slot) in the laptop(i3 8130U)...would it be better than 4+4 ....and will dual-channel work on 12 GB (4+8).

[AlHill]

You should ask your laptop manufacturer that question.

[n_scott_pearson]

Dual-channel support will be enabled regardless of whether you add a 4GB SODIMM or an 8GB SODIMM. The 8GB SODIMM will garner a better performing system simply as a result of the benefits of the additional 4GB of memory being available.

Hope this helps,

...S

[bhaskar]

Thank you!