Comments on: Here is Why You Should Fully Populate Memory Channels on CPUs Featuring AMD EPYC Genoa

By: Nejc

Nejc — Mon, 16 Sep 2024 12:18:36 +0000

I gotta be honest, I second what Vincele said. It depends on the budget and apps you’re using.

In my experience, there is practically run to run variance of a difference for rendering tasks – aka might not be worth the extra money for populating all the channels.

By: AK

AK — Sat, 14 Sep 2024 08:27:14 +0000

Wasn’t this always a question how the motherboard / memory controller is designed?
Whether its a dual, quad, hexa or octa channel design.
So the 1st question to me would be what the maximum number of channels is, that the particular mainboard supports. If it fits with the number of memory slots on board well, then it is a good idea to use them all.

By: jpuroila

jpuroila — Fri, 13 Sep 2024 07:36:39 +0000

So more memory channels means more memory bandwidth? Okay, but the pertinent question isn’t “How much does this increase the available memory bandwidth?”, it’s “How does this impact performance (in our use case)?” This entire article is saying nothing of value.

By: emerth

emerth — Thu, 12 Sep 2024 02:13:19 +0000

Thanks, @Chris S!

By: Chris S

Chris S — Wed, 11 Sep 2024 22:40:47 +0000

@emerth

Server OEMs put dummy DIMMs (blocks of plastic) in the slots if they are not populated. That ensures that the airflow profile is the same regardless of the number of DIMMs.

By: Rob

Rob — Wed, 11 Sep 2024 10:20:52 +0000

Micheal’s article: “DDR5 Memory Channel Scaling Performance With AMD EPYC 9004 Series” found that on the geometric mean using only 10 channels costs 10% memory performance with a potential savings of several hundred dollars or more. For some workloads the performance was equal.