Question Is it better use 2*16Gb mem kit or 4*8Gb memory kit in amd Ryzen

[hannibal]

Is it better use 2 16Gb mem kit or 4 8Gb memory kit in amd Ryzen system?
Is there performance difference if you use 2 or 4 memory stick, in older days it was better to use two big vs four smaller, but has the situation changed?
It seems Also that 8Gb sticks have better timing than 16Gb sticks. Any particular reason for that?

 

[wsmith198729]

Better or not depend on your mainboard. If mainboard support quad channel, you choose four 8GB. It will bring to your PC more speed.

 

[SkyNetRising]

Ryzen support only dual-channel. So 2 modules is better than 4.
For quad channel you'd need Threadripper.

 

[hannibal]

Thanks! Any info why those 16Gb memory modules seems to be slower than 8Gb ones? Single rank, douple rank?

 

[QwerkyPengwen]

They are not slower.

You can get 16GB sticks of really high speeds.

If you're talking about the timings, that's a whole other story, but to put it simply, the higher the speeds in MHz and the higher the capacity of the stick, the slower the timings, unless you pay an extreme premium in price for it to have shorter timings

 

[Danra]

The answer to your question, why do 16GB RAM have worse timings [slower] than 8GB is the density of the RAM. The more RAM you are accessing, the more demanding it is on the RAM. To have the same timing the 16GB module requires more voltage than the 8GB and you can only go so far in voltage before the life span of the RAM is impacted.

Now, I am speaking in general terms because RAM can be binned or have higher quality components for example, however the above is the answer to your question.

And, to your initial question, is it better to use 2 sticks of RAM or 4? The answer is 2 because two sticks of RAM is easier on the motherboard controller. The controller will have less work to do and run cooler, which impacts the lifespan of the controller. There again, I am speaking in general terms in order to keep my explanation easy to understand.

Note that I have a great deal of education in computer hardware and a vast amount of experience since I got into the computer field over 35 years ago, however, in the past I have confused individuals because I went into to much detail. So, I hope my simple explanations answer your questions.

If I have helped you please select my answer for two reasons, 1.) others that read this with the same questions will see the answer, and 2.) thanks is always appreciated by those of use here that try to help others.

 

[SkyNetRising]

because two sticks of RAM is easier on the motherboard controller. The controller will have less work to do and run cooler, which impacts the lifespan of the controller.

BTW - memory controller is built into cpu (not motherboard) for all modern cpus.

 

[Danra]

BTW - memory controller is built into cpu (not motherboard) for all modern cpus.

Thank you. Sometimes my mental memory slips with old and new hardware.


On newer motherboards the memory MOSFET or memory VRM will weaken over time if RAM is overclocked or run beyond the spec, which is usually what XMP technically does. Most motherboards have single phase PWMN integrated driver, however, I doubt the driver will fail unless defective.


EDIT: Spelling error...