[SOLVED] does 2666mhz ram bottleneck ryzen 5 3600 cpu?

[illusineer]

does 2666mhz ram bottleneck a ryzen 5 3600?

 

[Darkbreeze]

Bottleneck is not the right word here, but technically, yes. Literally, no.

What is does is not allow the platform to run at it's optimal performance level like it would with a higher speed memory kit. What is the model of your motherboard?

 

[illusineer]

asus rog strix x470-f. is it a massive performance difference.?I didnt really know about memory speeds affecting ryzen performance until recently. i discovered this when looking to upgrade from 2x8gb ddr4 2666mhz to another set of 16gb for a total of 32gb to occupy all my ram slots. but it's all very confusing what with ram sets and frequencies and timings. any upgrade advice?

 

[Darkbreeze]

Do you already have the 2666mhz sticks?

I don't know that the difference is "massive", but it could be "significant", especially given the fact that Ryzen 3000 natively supports 3200mhz memory and can support up to 3600mhz without the latency penalty from the memory controller decoupling from the infinity fabric.

 

[illusineer]

well I see a couple sticks of 3200mhz same amount of memory just a couple dollars more than the 2666mhz sticks I already got. no brainer? can I run two different frequency memory at the same time or does that not work? what percentage improvement is there from 2666-3200 in cpu bound applications on the 3rd gen 3600?

 

[Darkbreeze]

https://www.techpowerup.com/review/amd-zen-2-memory-performance-scaling-benchmark/2.html

It's not terribly evident, but there are differences. Surprisingly, the differences are bigger for gaming, where it usually is the opposite.

 

[illusineer]

ok here's a different question, can I run 4 16 gig sticks @ 3200mhz with my mobo+cpu combination? I read somewhere that am4 socket can only run dual channel(two sticks right?), which makes me wonder why that is if the motherboard supports 64gbs and there is 4 slots on the motherboard. that doesnt add up

 

[gskill support]

It is very stressful for the CPU memory controller so you may need to boost SoC Voltage to see if it is capable. Also, there is no guarantee the two separate kits can work well together. Will need to do some testing / troubleshooting to see what's going on.

 

[Darkbreeze]

Even with four sticks, it would STILL only be running in DUAL channel. Triple, quad, and higher channel memory architectures are ONLY found on HEDT and other high end platforms. Consumer memory architectures, so far at least, are pretty much always dual channel.

This is not a problem. This is by design. You will simply have MORE memory running in dual channel, ie, 64GB of dual channel operation, rather than just 32GB of dual channel operation.

However, as gskill support has mentioned, four sticks is a lot of stress on the memory controller and it won't always work depending on some variables. Higher end motherboards AND higher end chipsets, tend to offer better chances that four sticks (Especially at high speeds as with 3000mhz and higher speed kits) will run without problems that you have to work through.

Having a CPU that can be overclocked usually helps as well. Better quality, higher end memory kits that use top quality IC's (Memory chips) affect the equation.

But the biggest single factor is usually that all of the memory comes together in a matched set that has been tested to ensure all of the sticks are compatible with each other. Even then, SOMETIMES one of the sticks might not want to play nice with the others on a given motherboard, and the kit might need to be returned and try a different kit. Even the same kit model but a different actual kit can make the difference.

I've seen guys struggle with quad channel kits that come with 8 DIMMs, try everything, turns out ONE stick that does work but does not work WITH all the other sticks, is the problem. Return the kit. New kit. Works fine.

So yes, you can use four DIMMS and they can be in DUAL channel but you want to eliminate as many variables as possible.

 

[illusineer]

if I get a 4x16 kit, I can slot them into my motherboard but there is no guarantee I won't have to troubleshoot them since 4 dimms is harder on the memory controller. so is it more sensible in terms of compatibility just to go with a 2x16 kit @ 3200mhz with this type of motherboard? from what I gather it seems like my motherboard will probably last longer if it's not stressed by 4 sticks. or is the load it puts on the motherboard an issue worth dealing with? so long as I'm not at risk of breaking anything or having to make returns im willing to tamper with bios settings or what not to get 4dimm to work unless it's not worth it with this mobo.

 

[Darkbreeze]

On the X470-F, which is a very decent board, I'd say you stand a good chance of them working especially if you're going to be using the newer Ryzen lineup.

It's not likely to "damage" anything, or else they wouldn't PUT four DIMM slots on there. It's a different kind of stress. It's electrical and thermal stress. I have little concern with being able to get a 4 x8GB kit to run so long as you go with a decent quality set of sticks.

That will, obviously, not be sticks at the low end of the price range. But not necessarily terribly expensive either. DRAM prices are VERY low right now compared to, well, maybe ever, but certainly for years.

A 2 x16GB kit would be preferred though. Not only is it more likely to work out of the box, it's also less stress on the memory controller (Which is in the CPU, not on the motherboard) which means the CPU will likely run somewhat cooler than with a 4 DIMM kit as well. Plus, if you should need to add more memory down the road, then even though we prefer to buy them all at one time in a matched kit, you would at least have the option to do that.

If you are fairly certain you are for some reason going to be needing 64GB at some point, then it might make a lot of sense to go ahead and buy a 4 x16GB kit from the get go, because as mentioned, later down the road adding in another kit could become it's own complication.