Help needed choosing RAM for Intel build

[darael]

I'm considering an Intel build, based on an i5-14500. I don't overclock these days as I have no need for it.

Now I'm quite confused choosing DDR5 RAM for the Asus TUF GAMING Z790-PLUS WIFI motherboard. At first I was going to choose DDR5 4800 MHz, but after a bit of reading people seem to be saying to get the fastest RAM you can afford.

As I said I won't be overclocking, so what would be the point in buying DDR5 7600 MHz or whatever? Does the CPU's memory controller negotiate the speeds as required? And do the speeds change as per demand, rather than running flat out at max MHz all day?

Apologies for what are probably newbie questions, but I've found DDR5 speeds pretty confusing.

 

[darael]

It runs flat out.


Yes, but from what I can recall watching buildzoid's videos, 7200 is usually the point that the IMC can't be relied upon and YMWV.

That said, this was with higher-end K CPUs and the non-K i5 CPUs may have significantly weaker memory controllers due to two things: 1. the binning process and 2. they're probably based on the older 12th gen architecture as only the 14600 non-K has the Raptor Lake cache config of all the i5 non-K CPUs from 13th and 14th gen (2MB per P-core and 4MB per E-core cluster, up from 1.25MB per P-core and 2MB per E-core cluster).

If you absolutely DO NOT want to overclock then I'd buy either the Crucial Pro sticks (these can run without XMP/EXPO being enabled) or something like Kingston value memory. Be careful of the Corsair sticks because even though they're slow, they may still require XMP/EXPO and a higher than stock voltage. The compromise for running at 1.1v without XMP/EXPO is that they have higher latency than the gaming sticks.

The main circumstance that the higher speed RAM matters is if you're playing games at a low resolution (especially competitive esports) with a higher-end graphics card (e.g. 4070 Ti+), but in most other circumstances the performance loss is not very big.

Is there any particular reason why you want the 14500? I'd expect the 13600K/13600KF to be a better buy and a higher performer.

Having the RAM flat out puts me off a little, as I don't like the idea of continuously wasting energy when energy prices are as expensive as fragile as they are these days.

I think the last time I overclocked was when I had a Pentium 4, but these days I genuinely don't have a need for it. I have though about undervolting the CPU core, but the stability of the system usually isn't worth the measly savings.

I think I would compromise running RAM with less latency for a slightly higher voltage, just to help keep the system feeling responsive. My builds usually last me around 5 years or so, so this would also help future proof the build a little.

For me the RAM speeds would matter more for when I am encoding videos in HandBrake, building Windows ISO images from UUP dump, then working with the ISO images to customise them. The rest of the time the system remains relatively idle, web browsing, watching YouTube, films, etc.

I chose the 14500 mostly to help future proof the build. I never considered stepping up models from the previous generation and that's something for me to think about. Thinking about it, probably the K series put me off as I don't plan to overclock and these support faster RAM speeds. But I didn't realise the non-K CPUs have weaker memory controllers.

 

[darael]

Crikey, there's a lot to take in there, but thanks for your replies so far @Tetras

The system is going to be running 24/7, so power consumption is a consideration. If the new build uses less energy than my existing system then I'll be happy - if it's the same, then at least I'll be pleased it's not more.

I really doubt I'll need 64 GB of RAM, but I'll see what the costs are - if it's not too much more, I may as well go for 64 GB for the sake of future proofing the system. I am quite comfortable most of the time on 16 GB of RAM, unless I need compress a lot of files with 7-Zip.

Just so I've got this straight in my head, if I bought the i5-14500 non-K then I might as well just buy 4800 MHz RAM because the CPU's memory controller can't go faster, at least reliably? If I wanted to use faster RAM, say 6400 MHz, then I'd need a K CPU such as the i5-14500K?

I keep reading online that the sweet spot is 6000 or 6400 MHz, but I'm wondering whether to bother just for the sake of encoding now and again.