H12SSL and Understanding Memory Rank

AugustaLemke

New Member
Sep 6, 2021
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Once I get my processor, I was going to get one of the Supermicro boards (H12SSL-CT) and throw in a lot of memory.

I started doing the research on memory and found that Crucial only had the H12SSL-NT board for compatibility which I think is close enough:


I'm going to buy a few 32GB sticks, but I what I was shocked to see was that they are all the same price, regardless of rank.

I don't understand why this is the case, as I keep reading that single rank should be the most expensive. This makes things very difficult, because I cannot figure out which one to get for the best speed and performance.

Which is ideal in terms of speed and performance:

2 Rank x 4
2 Rank x 8
1 Rank x 4

Some sites I read say dual rank is better than single rank while others say the opposite. I cannot figure out a straight answer to this. I understand the technical meaning of dual vs single but in terms of performance, I'll end up finding another site that contradicts the previous one, causing confusion.
 

alex_stief

Active Member
May 31, 2016
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As soon as you have at least two ranks on each memory channel, performance differences between individual configurations become difficult to even measure.
This whole "single-rank better" comes from a different niche of performance pedants: overclockers on consumer platforms. With only one rank per memory channel, the strain on the memory controller is lower, which allows for higher memory clock speeds and lower latency compared to 2 ranks per channel. Which -depending on the workload- can be enough to offset the performance benefit of 2 ranks per channel.
Not too long ago, most server boards clocked down memory speed when populating many ranks per channel. That's generally no longer the case with modern platforms.
Since memory overclocking isn't a thing on the platform you have in mind, and it only has one DIMM slot per channel, just get the cheapest dual-rank DIMMs you can find.
 

111alan

Member
Mar 11, 2019
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Haerbing Institution of Technology
Actually from the measurement I did, 2 rank drams have slightly higher write and copy speed. Other than that there are little difference, so does x4 and x8. The single rank better saying is just about overclocking, since single rank drams have less chips, thus generate less noise on the PCB and put less stress to the IMC, so may overclock better.