Which is preferable for DDR4 Overclocking: 4x8GB or 2x16GB?

rohitparker

New member
For some reason, all of the high-frequency (4000 MHz+) and tightly-timed (e.g. 3600 MHz CAS 16) 32GB kits are sold in the 4x8GB configuration, and there are very few mentions of 2x16GB kits in motherboard QVL lists.


It makes me wonder: Is the 2x16GB configuration sub-optimal? Are DIMM manufacturers just taking the easy out and doubling up 2x8GB kits whenever possible, where they are focusing all their R&D? Are the 4x8GB kits getting higher-binned B-Die?

If my goal is 32GB @ 4000 MHz with the lowest latency possible, would I be better served overclocking a DDR4 3733/3866 2x16GB kit, or by tightening the timings on a DDR4 4000 4x8GB kit?
 
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Oussebon

Multiverse Poster
I've no idea. The forum is mostly for support with PCS systems. RAM overclocking is ultimately quite niche and I don't think the forum user base here has a huge amount of expertise in it.

You could try https://www.overclockers.com/ or https://www.overclock.net/

We may always have a closet expert here, but I'd certainly suggest also looking at forums more focused on overclocking.
 

Scott

Behold The Ford Mondeo
Moderator
The answer, for anyone searching, is that it would always be more optimum to use 2 over 4. There won't be any performance gain using the 4 slots but there may be a drop as you will be using resources that won't be taken up using the 2 slots (additiona; power and chipset processing). Always leaves the 2 slots up for future upgrading also.

Maximise the channels, minimize the slots. Always use 2 dimms over 1 for dual channel, always use 4 over 2 for quad etc.
 

ubuysa

The BSOD Doctor
The answer, for anyone searching, is that it would always be more optimum to use 2 over 4. There won't be any performance gain using the 4 slots but there may be a drop as you will be using resources that won't be taken up using the 2 slots (additiona; power and chipset processing). Always leaves the 2 slots up for future upgrading also.

Maximise the channels, minimize the slots. Always use 2 dimms over 1 for dual channel, always use 4 over 2 for quad etc.

Apologies if I've misunderstood, but aren't you contradicting yourself here? Your fist paragraph says 'it would always be more optimum to use 2 over 4' and your second says 'always use 4 over 2 for quad'.

Assuming the board supports quad channel I'd have expected 4 x 8GB to be a (slightly) better option than 2 x 16GB? Is that not the case then?
 

Scott

Behold The Ford Mondeo
Moderator
Apologies if I've misunderstood, but aren't you contradicting yourself here? Your fist paragraph says 'it would always be more optimum to use 2 over 4' and your second says 'always use 4 over 2 for quad'.

Assuming the board supports quad channel I'd have expected 4 x 8GB to be a (slightly) better option than 2 x 16GB? Is that not the case then?

Most of the systems that we talk about are dual channel. Nowadays there are boards coming out with quad channels.

For systems that are dual channel (Often with 4 DIMM slots) 2 should be utilised for maximum performance with minimum resource usage.
For systems that are quad channel (Often with 8 DIMM slots) 4 should be utilised for maximum performance with minimum resource usage.

My last statement was to clarify that less is not better, you want to maximise the channels. With a dual channel configuration 2 is better than one, with a quad channel configuration 4 is better than 2.

There are triple channel options as well, usually with 6 DIMM slots. 3 would be the optimal here, rather than 1, 2, 4, 5 or 6.
 

Oussebon

Multiverse Poster
I think the '2 always better than 4' was based on the assumption that it was a regular consumer mobo with dual rather than quad channel. Which is the same basic assumption I made tbh.

TL;DR seems to be 1 DIMM per channel = optimal

Edit: what he said
 

ubuysa

The BSOD Doctor
Most of the systems that we talk about are dual channel. Nowadays there are boards coming out with quad channels.

For systems that are dual channel (Often with 4 DIMM slots) 2 should be utilised for maximum performance with minimum resource usage.
For systems that are quad channel (Often with 8 DIMM slots) 4 should be utilised for maximum performance with minimum resource usage.

My last statement was to clarify that less is not better, you want to maximise the channels. With a dual channel configuration 2 is better than one, with a quad channel configuration 4 is better than 2.

There are triple channel options as well, usually with 6 DIMM slots. 3 would be the optimal here, rather than 1, 2, 4, 5 or 6.

Thanks for this! I wasn't barking up the wrong three then. :sweatdrop:
 

Scott

Behold The Ford Mondeo
Moderator
Thanks for this! I wasn't barking up the wrong three then. :sweatdrop:

No, not at all. The difficulty in explaining it is due to there often being double the amount of DIMM slots to channels :D

As Oussebon states, fill the channel(s)... not the slots :)

Edit: I've never overclocked a 4ch system before so I'm presuming that filling 2 channels would be the way to go but it may work the same as a dual channel board and sticking to one might be better. No real world experience here so would be interested to try it out.
 
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Tony1044

Prolific Poster
As someone who doesn't even own a desktop, let alone an overclocked one, is there much/any extra heat generated in the RAM by overlocking? Does having larger gaps between RAM make any difference?

Idle curiosity asking.
 

Scott

Behold The Ford Mondeo
Moderator
As someone who doesn't even own a desktop, let alone an overclocked one, is there much/any extra heat generated in the RAM by overlocking? Does having larger gaps between RAM make any difference?

Idle curiosity asking.

RAM tends to get very hot when being worked hard regardless. As much as the OC may add some additional heat I don't think it's something that is ever considered. The gap between the DIMMs is a good point though, anything to help with airflow and cooling is always a bonus. For serious overclockers there are extended fin heat sink DIMMs available. I had these in one of my systems years ago, I didn't worry or monitor the RAM temps but I wanted to have any advantage that I could.

My current system has vented heat sinks on the RAM. (Ballistix Tactical).

Managed 2nd and 3rd with my current desktop but couldn't beat out top spot :D

http://www.superpi.net/Scores/?acti...rm=Desktop&series=Core+i7+3000K+Series&rpp=20

Overclock was 5GHz and not 3.8 as reported.
 

Tony1044

Prolific Poster
Now this is odd...on this particular page I get it showing two pages and the arrow / last double arrow.

But when I click the number 2, the arrow or the last arrow, it takes me back to post 1...

So far not seeing it on any other page.

Meh...it's Friday. Even the forum software is ready for the weekend!

Edit: Of course...my own post goes to the top of page 2!
 

ubuysa

The BSOD Doctor
Now this is odd...on this particular page I get it showing two pages and the arrow / last double arrow.

But when I click the number 2, the arrow or the last arrow, it takes me back to post 1...

So far not seeing it on any other page.

Meh...it's Friday. Even the forum software is ready for the weekend!

Edit: Of course...my own post goes to the top of page 2!

Do you use a forum style other than the default?
 

Oussebon

Multiverse Poster
That seems to happen when a post is moderated, the forum gets confused about how to count posts and what page to put them on. Somehow the OP's post went into moderation, despite the fact I banned them, so they couldn't edit it, and I don't think any of the mods edited it either.
 
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