Why is it best to have fast RAM

Minibiker · 13 Sep 2017 at 20:38

Hi all

Been having a debate with a guy from work, Hes thinking of building a Ryzen system and I told him that you'll get better performance by adding some RAM 3000mhz+, He seems to think that's a lot of rubbish and im just trying to spend more of his money...

Can any explain to me why the higher RAM speed is better so when I see him tomorrow I can explain to him

Thank you

Rroff · 13 Sep 2017 at 20:42

Ryzen platform seems quite sensitive to RAM configuration - not just indiscriminate turning up frequency (depends a bit on what applications you are running) when transferring data between cores that aren't "local" to each other (to simplify) - faster RAM can significantly reduce any penalty that arises in that situation which can be seen with some games, etc. up to a point the performance gain scales quite close to the increase in RAM frequency so it can be quite worthwhile. Performance gains in the region of 20% aren't unusual.

Intel platforms usually (though a bit less the case with some of the newest CPUs) have more bandwidth than they actually can utilise much of the time so performance gains from faster RAM are minimal unless you are doing things like quad SLI, etc. and sometimes you can even get a moderate performance boost from tightening up timings over going for raw frequency (more limited to quad channel memory platforms and specific applications). Performance gains are usually more in the region of 5% except for some of the very latest using DDR4 where you can see bigger gains in specific applications.

Short answer - Ryzen there is a moderate potential performance gain from faster RAM, Intel much much more situational and generally less of a benefit.

Minibiker · 13 Sep 2017 at 20:55

Thank you @Rroff that's a great answer and clears it up perfectly for me... I shall put that across to him :cool:

Ste · 14 Sep 2017 at 09:20

In really simple terms think of Ryzen as two CPUs in one, two sets of 2, 3 or 4 cores and the way that they communicate with each other is dependant on memory speed.

Minibiker · 14 Sep 2017 at 12:19

Ste said:
In really simple terms think of Ryzen as two CPUs in one, two sets of 2, 3 or 4 cores and the way that they communicate with each other is dependant on memory speed.

Thank you

very helpful information guys