AM4 & TR4 Memory Timings and costs, etc.

[w0lfram]

I am looking at building two new rigs in the next few weeks, based on Ryzen 1600x and 1900x.

I am looking at 3600Mhz sticks of memory, but wonder how much the CAS timing effect the over-all bendwidth or thruput. I remember seeing a table/chart, but with ThreadRipper being released I might be looking at possible 3800, or even possible 4000Mhz memory if the "Infinity Fabric" can handle it.

I am new here and would really like to explore and expand my options. So, any help, or discussion is welcomed.


examples:
3200Mhz @ CAS 14 -vs- 3600Mhz @ CAS 16 -vs- 3800Mhz @ CAS 18

 

[Davros]

from another post of mine since you asked about price

Im quite shocked at the effect ram speed has on price

 

[w0lfram]

It is a start, thnx.
But, I am more concerned about performance in clocks on Zen's "Infinity Fabric". Was just hoping to find a discussion on this here, or elsewhere. Not really "social media" adjusted.

I have seen in the past, matrices/spreads that have performance metrics for a CAS vs Mhz. Perhaps x399 TR4 uses the same timings, etc ?


Also, for conversation sake, how easily can say 4200Mhz @ 19cas be "downclocked" to a 3800Mhz @ 17cas, for example. Or can one even stretch it & dwnclk to 3600Mhz @ 16cas ??

Or is it more or less an art still ?