RAM Latency

[kvasir]

Are you effectively trying to say that we do not have enough information to judge whether the RAM with higher frequency or the RAM with lower latency is better for us?

The DDR5-5600 that you cited is faster in every regard.

* DDR5-5600 CL28-34-34-89

Maximum transfer speed: 44.8 GiB (5600 M/T * 8 B/t)
Bus speed: 2800 MHz (5600 M/T * 1 / (2 T))
CAS latency: 10 ns (28 / 2800 MHz)

* DDR5-4800 CL38-38-38

Maximum transfer speed: 38.4 MiB
Bus speed: 2400 MHz
CAS latency: 15.8 ns

If the only question is which memory device serves data faster, then it is the DDR5-5600. It both transfers more per second and starts transferring quicker. In that sense it's enough information.

If this is a question on the measurements by And using different DDR4 memories then there might not be enough information to interpret it. At least drawing the conclusion that the difference was due to CAS latency doesn't seem right.

[RobertJasiek]

Further considerations:
- Does the RAM cooler fit under the CPU cooler?
- Does the mainboard or RAM manifacturer confirm compatibility for a model set of a particular GB size and number of occupied DIMMs?
- Is it RGB or not and which does one prefer?
- Is the price difference too large?
As it turns out after closer inspection, I may have to bow to such soft criteria. (I do not choose other mainboard and CPU cooler just to get the perfect RAM modules.)

[RobertJasiek]

https://timdettmers.com/2018/12/16/deep ... Clock_Rate

Tim Dettmers writes that fast versus slow RAM makes 0 ~ 3% speed difference for machine learning. I conclude that spending €30 on much faster RAM might be worth it (ca. 1.5% of a €2000+ desktop price) but not €50. More important may be RAM stability and longevity.

[And]

I changed the processor to Ryzen 5 (there was an athlon x4), the memory is the same, (DDR4 2667 20 19 19 43): 10739, 11473, 11164 visits.
started tuning katago again, after: 10964

[RobertJasiek]

As it has turned out, the alleged 4 DIMM option was a mistake on the mainboard reference page. After more careful inspection, I have also noticed that the smallest CL stick is incompatible to my chosen board. The cheapest module has not been readily available. So I am settling for some reasonable compromise for a typical market price after all;) It remains the most important that RAM sticks do work at all together with the chosen CPU and mainboard! Nevertheless, the discussion has been interesting and might help others.