[SOLVED] If I use fast memory, do I have to use fewer DIMMs?

[Rich99]

I just purchased an ASRock X470 Master SLI/ac motherboard and Ryzen 7 2700X CPU, and am about to purchase memory for it. I'll go for 2x16GB for now, but will eventually upgrade to 4x16GB. The documentation implies that if you use higher-speed memory, you can only use 2 out of the 4 DIMM slots.

I need to use all four slots, as I'm planning on maxing out the memory on this board. Am I reading this chart wrong? Is it actually possible that using 3200 MHz sticks would mean I can only use 2 slots?

This chart is from https://www.asrock.com/mb/AMD/X470 Master SLIac/index.asp#Specification

SR: Single rank DIMM, 1Rx4 or 1Rx8 on DIMM module label
DR: Dual rank DIMM, 2Rx4 or 2Rx8 on DIMM module label

EDIT: Added CPU and memory info

 

[kerberos_20]

it also depends on which cpu u get, but more or less, more sticks = less max clock as teh mem controller has to work harder
bumping up mem controller voltages and toyin with RTT/CAD can help a bit raising frequencies

 

[Rich99]

it also depends on which cpu u get, but more or less, more sticks = less max clock as teh mem controller has to work harder
bumping up mem controller voltages and toyin with RTT/CAD can help a bit raising frequencies

Thanks for the info. I bought a Ryzen 7 2700X CPU (added that to my original post).

If I buy 3200 MHz and put in 4 DIMMs, will the memory just slow down to its maximum 2933/2667, or will the MoBo fail to recognize 2 of the DIMMs?

 

[Third-Eye]

Thanks for the info. I bought a Ryzen 7 2700X CPU (added that to my original post).

If I buy 3200 MHz and put in 4 DIMMs, will the memory just slow down to its maximum 2933/2667, or will the MoBo fail to recognize 2 of the DIMMs?

What capacity are the modules and what kit model. If you bought a 4x8GB kit, then you can likely run at 2933-3000MT/s. If it's a 4x16 kit you will be limited to 2666-2800MT/s. If you run 2x16GB you may be able to run 2933-3000MT/s. If you only had 2x8GB you could possibly run up to 3466MT/s.

 

[Rich99]

What capacity are the modules and what kit model. If you bought a 4x8GB kit, then you can likely run at 2933-3000MT/s. If it's a 4x16 kit you will be limited to 2666-2800MT/s. If you run 2x16GB you may be able to run 2933-3000MT/s. If you only had 2x8GB you could possibly run up to 3466MT/s.

I don't have a specific memory model in mind. I'm planning to start with 32 GB (2x16), but I expect to upgrade to 64 GB (4x16) in the future.

 

[Calvin7]

You show chart of memory configurations for Matisse CPUs, but you don't have a Matisse CPU.

 

[kerberos_20]

You show chart of memory configurations for Matisse CPUs, but you don't have a Matisse CPU.

true

but i wouldnt thrust it that much, mine x370 board with 1st gen ryzen can handle 4 dual sided sticks at 2666 and two dualsided at 3400

 

[Rich99]

You show chart of memory configurations for Matisse CPUs, but you don't have a Matisse CPU.

Wow - Good catch! I was looking at several CPUs, and must have gotten info confused.

You've just saved me some real potential headaches! I was looking at multiple processors, I must have gotten things confused. I've corrected the chart in my original post. Looks like the mem speeds I need are even lower than I originally thought. Thanks!

 

[kerberos_20]

Wow - Good catch! I was looking at several CPUs, and must have

You've just saved me some real potential headaches! I was looking at multiple processors, I must have gotten things confused. I've corrected the chart in my original post. Looks like the mem speeds I need are even lower than I originally thought. Thanks!

that depends, listed speeds are just for reference, overclock is still possible
same site u posted picture from
AMD Ryzen series CPUs (Pinnacle Ridge) support DDR4 3466+(OC) / 3200(OC) / 2933(OC) / 2667 / 2400 / 2133 ECC & non-ECC, un-buffered memory
OC clocks arent guaranteed, and with 4 sticks u will still need bump up some settings for higher clocks
here some references for 4 sticks
https://www.overclock.net/forum/11-...duel-rank-2-x-f4-3200c14d-32gtz-kit-64gb.html

 

[Third-Eye]

Wow - Good catch! I was looking at several CPUs, and must have gotten info confused.

You've just saved me some real potential headaches! I was looking at multiple processors, I must have gotten things confused. I've corrected the chart in my original post. Looks like the mem speeds I need are even lower than I originally thought. Thanks!

The speeds I listed in my last post were specifically for Ryzen 2000 in dual rank configurations (2x16GB or 4 modules) and I should have mentioned that before.