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.

 

[Tetras]

And do the speeds change as per demand, rather than running flat out at max MHz all day?

It runs flat out.

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?

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.

 

[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.

 

[tamzzy]

if you don't want to overclock just get a b760 board and some ddr5 6000 ram instead
ram power consumption are not like cpus and are not significantly different regardless of speed

if you're desperate to get the z790 boards then really you should be getting the -k series chips (even if you don't overclock) because you then have the advantage of the raptor lake cores (1 generation newer) whereas the non-k cpus are based on the alder lake cores (12th gen) despite being labelled as 13x00 and 14x00 chips

 

[Tetras]

But I didn't realise the non-K CPUs have weaker memory controllers.

I don't have any hard facts to support that, but even on Intel ark the non-K i5 CPUs have a lower official memory spec for 2x sticks (4800 versus 5600 for the K CPUs), though I think it is as much because they're derived from 12th gen dies as the binning process, because the 14600 non-K (which has the raptor lake cache config) gets upgraded to 5600 and so far as I can see, this is the only non-K i5 CPU that is rated for 5600.

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.

In previous Intel generations the i5 CPUs were the same CPUs, but with 12th gen onwards Intel has changed this policy and the i5 K CPUs are significantly different to the non-K CPUs, with the 14600 non-K being the only exception.

E.g.
12400-12600 non-K: 6 P-Cores & 0 E-Cores (die: H0). Memory: 4800.
12600K: 6 P-Cores and 4 E-Cores (die: C0). Memory: 4800.

13400-13600 non-K: 1.25MB per P-Core, 2MB per E-Core cluster (die: C0). Memory: 4800.
13600K: 2MB per P-Core, 4MB per E-Core cluster (die: B0). Memory: 5600.

14400-14500 non-K: 1.25MB per P-Core, 2MB per E-Core cluster (die: C0). Memory: 4800.
14600 non-K: 2MB per P-Core, 4MB per E-Core cluster (die: B0). Memory: 5600.
14600K: 2MB per P-Core, 4MB per E-Core cluster (die: B0). Memory: 5600.

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.

You might want to look at this article:

Impact of DDR5 Speed on Content Creation Performance (2023 update)

DDR5 memory has kits rated for up to 8400 Mbps, while desktop CPUs only officially support up to 5600 Mbps. How much does running at official specifications actually impact performance in common content creation applications?

www.pugetsystems.com

Puget actually advised you don't overclock as a creator though, which I don't think you'll find as a recommendation anywhere else:

What this testing has solidified for us is that if you are looking for the best mix of performance and stability, using RAM that matches the CPU manufacturer’s specifications is probably the right way to go. And to be clear, we are talking about the officially supported RAM speeds, not any of their “optimized for best performance” recommendations.

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.

The impact of RAM on power usage is very small, ram sticks only take a few watts, but they do increase CPU power consumption at idle and under load in a more significant way, though you'd usually only care about that if the PC is on 24/7.

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 an AMD build I think buying faster RAM would make sense as future CPUs on the socket could bump up the minimum spec quite a lot, but for Intel, I don't think I'd worry too much. I suppose if you buy 64GB there's a possibility you could reuse it with a future build, so in that sense buying 4800 may be unwise.

A compromise would be to buy memory that you CAN overclock, but also runs happily at the stock speed.

If you get a non-K CPU then that would be memory that can run @ 4800 and with a K CPU, memory that can run @ 5600.

My basket at OcUK:

• 1 x Crucial Pro 64GB (2x32GB) DDR5 PC5-44800C46 5600MHz Dual Channel Kit (SKU: MEM-CRU-01085) = £179.99
• 1 x Kingston FURY Beast EXPO 32GB (2x16GB) DDR5 PC5-48000C36 6000MHz Dual Channel Kit (KF560C36BBEK2-32) (SKU: MY-29T-KS) = £119.99

Total: £303.97 (includes delivery: £3.99)​

The first set operates without EXPO/XMP and will run at the stock speed of a K CPU.

The Kingston memory in the datasheet says that it has an alternative JEDEC speed of: DDR5-4800 CL40-39-39 @1.1V, which would be suitable for a non-K CPU.

 

[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.

 

[Tetras]

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?

The official rating from Intel for non-K i5 CPUs is 4800 (for 2 sticks) if you don't want to overclock the CPU/memory, but I think you'd need a REALLY poopy IMC to only achieve 4800.

Realistically, I'm sure 6000 would be achievable, but I don't have any samples and I don't know where you'd find someone/somewhere that has that data. All I can do is guess from what 12th gen CPUs achieved, since they apparently have the same die as the i5-14500.

The i5-K CPUs are likely to achieve higher speeds because they're based on newer silicon/architecture from the Raptor Lake line, so I'm pretty confident that 6000 or 6400 would be no problem at all for a 13th or 14th gen i5-K. The stock rating for these has been upgraded to 5600, which suggests that Intel also agree they have better memory controllers on average.

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.

Yeah, 6000 low latency seems to perform as well as anything, but part of the reason that 6000 is widely recommended is because Ryzen 7000 CPUs can run 1:1 with their infinity fabric comfortably @ 6000 (up to a max of 6400), which is an architectural novelty that doesn't apply to the Intel CPUs. Ryzen can now run much higher speeds, but the benefit of those speeds for not running 1:1 doesn't appear to be worth it, especially when factoring in the added cost of the memory.

I might as well just buy 4800 MHz RAM

If you do for the i5-14500, I would not buy 4800 because 1. your future re-use is going to be limited in 5+ years time because this will be VERY slow and 2. the cost benefit of 4800/5200 memory is very small and I don't think it is worth it.

My choice for stock running would be to either buy a K with the Crucial Pro 5600, or buy a non-K with the faster Kingston kit that has a JEDEC profile for 4800 @ 1.1v. There are other kits with a 4800 profile that runs at 1.1v, e.g. this Corsair kit, so you have more options if there is a good deal going at the time you buy (this kit seems to be decently priced at the moment, around ~£90).

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.

It is hard to find good information on this, but from what I'm aware, the newer Intel CPUs have followed Ryzen in bumping up the voltages if you enable EXPO/XMP and the CPU can also idle at a higher power draw.

I think the impact of EXPO/XMP at idle is in the region of 8-10 watts, so not the end of the world and can be easily munched by a bad motherboard, or a poorly configured BIOS.

Idle power consumption for 24/7 needs A LOT of research to buy the optimal parts, so if you're really serious about that, it is well beyond the scope of a few words in this thread.