Ram explanation please

[fightingfi]

in the easist most simple way plz explain why higher ram has higher cas and some ram while better has lower cas newer ram i see has like 19 and other are 14 wouldnt you want lower cas of 14 ?

 

[modi123]

Can you throw some punctuation in there? I get part of what you are saying, but other sections are questionable.

.. but, ah.. yeah.. maybe look at this?
https://www.pbtech.co.nz/news/732/Choosing-the-right-RAM-modules
https://www.crucial.com/usa/en/learn-with-crucial/about-memory/ram-speed-vs-cas-latency

 

[tedych]

Lower latency = better, always. Manufacturing tech does not advance so fast as frequency goes up, so latency goes up as well. (CAS) Latency doesn't tell everything and it's far from 1:1 relation to performance, otherwise you'd have DDR4 3000/C16 being no more performant than DDR3 1500/C8 .

 

[pitingres]

Faster RAM usually has higher CAS numbers because the CAS spec is in clock ticks. For instance, 3000CL15 and 3200CL16 are exactly the same latency, 10ns in both cases.

 

[dasa]

3000c15 3200c16 3600c19 use similar cheap ram chips but people that don't know any better see the bigger numbers and assume its better when really other than a little more bandwidth there much the same.

3200c14, 3600c15, c16 use more expensive chips Samsung b die.

It gets more complicated though as if the mb bios screws up sub timings with the fastest kit it may be the slowest without manual tuning.

 

[serial__thrilla]

The higher in the MHz clock of the RAM you go, the higher a numerical value you have to set the CAS latency to. However, setting the CAS latency to a higher numerical value means you make it slower to react to things that happen within it.
I know this is confusing, but when it comes to RAM special timing settings, the lower the numerical values, the more efficient (read - faster overall) your RAM may be.

All the special timings of the RAM (RAS, CAS, etc) are responsible basically for the responsiveness of RAM to the events that take place inside it. The clock speed (RAM's MHz) might not matter (or make all that much of a difference) once you reach a certain RAM MHz speed point.
Sometimes (and this is just an examples), DDR4 3200 may exhibit a lower band of speed than a DDR4 3000, because of not the loss of 200MHz in speed, but in a gain of a bunch of internal granular RAM chip timings that the DDR4 3000 has, when it is fine-tuned.

This has been the case for decades now, with main system RAM, since the times of the DDR 1 or DDR 2. You should read up on this, after a googel seerch.

In closing, a stick of DDR4 3000 might exhibit a higher benchmark of GB/s than a stick of a DDR3200 just due to to its finely tuned timings.