Ryzen 5000 memory layout - 2x8GB vs 4x8GB vs 2x16GB - Single Rank vs Dual rank?

Hi All

First time poster, longtime lurker.

Gamersnexus video on memory config with Ryzen 5000
I saw Steve from GN’s video( on some quite significant performance differences between 2x8GB and 4x8GB performance differences when using Ryzen 5000

They mentioned speaking to Wendell about it and he indicated that 2x16GB of single rank was the best config he has seen. He also mentioned interweaving playing a role (I don’t understand how).

I am curious as to the fundamentals impacting this. Without Wendel’s observation on 2x16GB, I would immediately assume that GN’s observation meaning that Dual Rank memory would be faster that single rank. but I also realized that its normally the opposite.

Should I stick with my 2x16GB memory order?
I have a 5950X with a Aorus Master X570 board and 2x G-skill Ripjaw 16GB 3600mhz CL16 memory on order.

I am doing a mix of IT, media and data production work and some nighttime gaming (usually grand strategy). Getting the 5950x over the 5900x since where I live (South Africa), shipping and taxes have closed the price gap (790 vs 1050) and I would like to be able to game, while video renders run in the background. I also tend to hold onto my hardware in about 4-6 year cycles.

I would hate to leave performance on the table, since I am ordering all new parts. Also if I need to upgrade to 4x 16GB RAM later, would I be seeing a drop in performance and should I rather go with 2x 32GB now?

Anyone else have some more information about this?

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I am more curious how Wendel has come to the conclusion that 16x2 RAM is the best config. I highly suspect he used an ITX board for this.

He does gush over that thing doesn’t he.

at the same time, I found a discussion with Dr Ian the other day, where they advised using dual rank 2x 16GB dimms and steering away from single rank, unless you go with 4 Dimms

I assume that Steve might have misspoke in his video

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I’d like to correct you here, it’s “interleaving”.

According to much of buildzoids testing it seems that was kinda already the case with Zen 2, although he never tested it in games.
I’m going to link to one of the videos he made about that:

Since we haven’t seen any config benchmarks with 2x16GB DIMMs yet I would suggest either waiting a little bit or go with 4x8GB since that one was tested.

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also…

why not 4x16?

Steve said in his video he does not have single rank 16GB sticks and that primarily it was more about number of sticks than overall size as the games that benefit fit in around 7800MB worth of the 16GB minimum they use so it was not a size restraint but just adding more sticks gave more performance.

If the best is 2x single rank 16GB sticks and 4x 8GB sticks have shown to be better than 2x 8GB sticks. The very best may well end up being 4x single rank 16GB sticks. But Wendell has only demonstrated a 2 slot itx board and Steve does not have the sticks to try it… Yet.

Is there now faster ECC available for Ryzen? I haven’t found any yet…

Afaik the fastest is still 3200.

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Kind of surprised this is not a bigger discussion…

Let me point out that we need a bigger data set :upside_down_face:

More benching needs to be done.

Ty Steve from Hardware Unboxed

The more I look into this the more confused I am.

It seems like the answer is to get either a 4x8gb DDR4-3200 CL14 kit or a 2x16gb DDR4-3600 CL16 kit between what GamersNexus, Wendal, and Hardware Unboxed are saying. I think the weird part is figuring out of the 2x16gb sticks are single or dual rank but it’s unclear how to know if you have dual or single rank.

Some where else I read that 2x16gb is always dual rank and then someone else said it depends on how new the 2x16gb kits are. There also isn’t a discussion around quad rank which I’m guessing isn’t really meant for normal desktop machines but does this play a factor also for Zen 3?

Generally a 4x8 3600 CL 16 with decent timings is cheap enough and performs well enough that it will not matter much. Tweak tuning for small gains and higher cost is were this lies.

The 3200 as much about compatibility even tho it has solid performance but far more expensive.

Same thing with 3800 and up ram…you rapidly start losing the performance for an ever increasing cost.

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I wonder how well 4x16GB would do

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As @SapphironZA mentioned I’m also pretty sure that Steve mispoke and actually meant dual rank. Buildzoid’s video @Hako linked also points in that direction.

This again points to dual rank being best:
2x8GB SR < 4x8GB SR < 2x16GB DR < 4x16GB DR

The sweet spot is 2x16GB because of dual rank and dual channel.

I was kind of waiting on Wendell’s video on it. I have not personally ran 16g sticks. Little curious about it.

should be out soon, sent Steve all the stuff

should be a good one. The answer, like all answers, is IT DEPENDS :smiley:

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Isn’t “Go with max supported sticks for platform” usually best strategy? I’m planning 2x32GB, and they will probably be DR because current chip manufacturing limitations?

No… mostly because larger capacities stress the memory controller more thus reducing ability to run at much higher frequencies . If I have that correct ? Some of the limitations are very much platform dependent . What cpu /motherboard / os / use case

I agree on “platform dependent” part, its pretty obvious and always been the case, since 8086.
But I heard that “stress controller” stuff few times already. What’s that even mean, and how it would work?
From what I understand 2x32GB DR is electrically equal to 4x16GB SR, except memory modules are further away from each other, because traces.
So how this “stressing” would lower clocks more on two modules instead of four? And I still need at least 64GB at the end of the day…

I guess stress is not a hard enough term but damage is.

Since your memory is ultimate middleman any errors or problems tend to lead non functional. data loss

One of these computer scientists floating around here could explain it better I can.

I am literally just the average joe :slight_smile: