Question Ryzen and Memory speeds

[Agera One]

I heard that using more number of memory sticks on Ryzen makes them to run at a reduced speed. Is that true?
Is it better to go for 1x16 GB stick and use max speed but single channel or get 2x8GB and use dual channel but with a clock lesser speed?
Is there any link where I can learn why in detail?

 

[MrN1ce9uy]

That's not necessarily true.

Rule #1: Always use RAM sticks in pairs. Dual-channel is always better than single-channel.

Next, sometimes using all 4 RAM slots can cause instability. So, sometimes, 2 sticks runs better than 4. Also, 4 sticks have no benefit over 2 sticks on a dual-channel system. You would require a High-End Desktop (X399; ThreadRipper) to take advantage of quad-channel RAM.

 

[sizzling]

That's not necessarily true.

Rule #1: Always use RAM sticks in pairs. Dual-channel is always better than single-channel.

Next, sometimes using all 4 RAM slots can cause instability. So, sometimes, 2 sticks runs better than 4. Also, 4 sticks have no benefit over 2 sticks on a dual-channel system. You would require a High-End Desktop (X399; ThreadRipper) to take advantage of quad-channel RAM.

I started a thread after seeing 2 vs 4 stick gaming benchmarks on dual channel systems which shows better performance with 4 sticks. I was quite surprised when I saw this but after more digging found this to be supported elsewhere too. Here https://forums.tomshardware.com/threads/2x8gb-vs-4x4gb-gaming-comparison-intel.3479216/

 

[MrN1ce9uy]

I started a thread after seeing 2 vs 4 stick gaming benchmarks on dual channel systems which shows better performance with 4 sticks. I was quite surprised when I saw this but after more digging found this to be supported elsewhere too. Here https://forums.tomshardware.com/threads/2x8gb-vs-4x4gb-gaming-comparison-intel.3479216/

Wow, I think I now have a reason to buy more RAM.

 

[sizzling]

Wow, I think I now have a reason to buy more RAM.

I’m not recommending it, your point about possible stability issues I believe is true. Just these results were really surprising too me and against what nearly everyone says.

 

[Agera One]

Okay guys, what's with the clock speed reduction when using with Ryzen? Does AMD website have any news on that? Link please?

 

[sizzling]

Okay guys, what's with the clock speed reduction when using with Ryzen? Does AMD website have any news on that? Link please?

When using dual sticks/channel there is no reduced speed. There is a possibility of having to reduce the speed manually with 4 sticks to obtain stability but this is also true with Intel.

 

[MrN1ce9uy]

Okay guys, what's with the clock speed reduction when using with Ryzen? Does AMD website have any news on that? Link please?

There were speed limitations with 1st and 2nd-gen Ryzen. 1st-gen was mostly limited to 2933MHz and 2nd-gen was limited to 3200MHz. 3rd-gen can go higher, like 3900Mhz or something??

 

[hotaru251]

RAM is always better dual channel vs single channel (quad channel should share this, but its only really on HEDT or server boards).
Think of it as a highway....2 lanes are better than 1 lane for stuff to stay moving at a good pace.

RAM OC however wants as few ram sticks as possible (while retaining dual channel) and timings are important for ryzen. (can get more performance out of tuning timings than making them faster)

This is why most every OC person will only use 2 sticks (and stuff like evga's dark boards only HAVE 2 ram slots to allow better ocing).

3rd-gen can go higher, like 3900Mhz or something?

depends on if its supported by motherboard but some ryzen 3 boards support well over 4000 speeds.

 

[CountMike]

There were speed limitations with 1st and 2nd-gen Ryzen. 1st-gen was mostly limited to 2933MHz and 2nd-gen was limited to 3200MHz. 3rd-gen can go higher, like 3900Mhz or something??

Those were limitations with motherboard and BIOS, not Ryzen itself.
The reason why it's more difficult to run higher speeds RAM when using 4 sticks is mostly that there are two memory controller channels in the CPU and using both puts more load in such IMC. With good RAM and BIOS settings even that is achievable. Best memory is still made with Samsung b-die chips.
My 1600xx and 1700x on Asus prime x370 pro run 4 sticks of b.die RAM at 3200 MHz Cl 14 just fine after at that time latest BIOS was flashed.
2700x and now 3700x on Asus Prime x470, both run Kingston 3600MHz (b-die) RAM at 3600MHz Cl16 at full speed but only with 2x8GB, don't have kit of 4 to try but I'm sure it would work with 4 sticks too.
Tried this same RAM at 4000MHz too but but latency went sky high (Cl 28) negating any gains.

 

[Agera One]

Those were limitations with motherboard and BIOS, not Ryzen itself.
The reason why it's more difficult to run higher speeds RAM when using 4 sticks is mostly that there are two memory controller channels in the CPU and using both puts more load in such IMC. With good RAM and BIOS settings even that is achievable. Best memory is still made with Samsung b-die chips.
My 1600xx and 1700x on Asus prime x370 pro run 4 sticks of b.die RAM at 3200 MHz Cl 14 just fine after at that time latest BIOS was flashed.
2700x and now 3700x on Asus Prime x470, both run Kingston 3600MHz (b-die) RAM at 3600MHz Cl16 at full speed but only with 2x8GB, don't have kit of 4 to try but I'm sure it would work with 4 sticks too.
Tried this same RAM at 4000MHz too but but latency went sky high (Cl 28) negating any gains.

How to find whether the stick uses b-die chips or not?

 

[CountMike]

How to find whether the stick uses b-die chips or not?

B-Die Finder

Find Samsung B-Die DDR 4 memory kits on Amazon, Newegg and many more.

benzhaomin.github.io

 

[EndEffeKt_24]

Another good alternative for budget friendly RAM with good overclocking potential is Micron Rev.E those can be found in most Ballistix kits like the Sport LT 3000 Cl 15.