Question Trying to Understand RAM Overclocking

[jaydub868]

I have a question as to what exactly constitutes memory overclocking. On Newegg, the lowest rated DDR5 RAM modules are DDR5 4800. So, if I install those modules and run them at 2400Mhz (one half because double data rate memory), That clearly isn't overclocking. The highest rated DDR5 RAM for sale is DDR5 8400. If I install and run them at 4200Mhz, is that considered overclocking?

The reason I ask is that I want to update my PC with Arrow Lake using an Asrock Z890 Pro RS WiFi White motherboard, and I don't particularly feel the need to overclock the RAM. I'm trying to figure out what's the fast frequency RAM I can get without overclocking. The RAM specs for that motherboard state "Supports DDR5 non-ECC, un-buffered memory up to 8666+(OC)". What's with the "(OC)" which I assume means overclock.

 

[Lafong]

That board's spec sheet says the following. "Over-clocking" or not, the key words are "up to". Your mileage is unknown until you actually assemble the stuff and see what happens if you attempt to run at higher speeds and face stability issues.

- Dual Channel DDR5 Memory Technology
- 4 x DDR5 DIMM Slots
- Supports DDR5 non-ECC, un-buffered memory up to 9066+(OC)*
- Supports Clocked Unbuffered DIMM (CUDIMM)
- Max. capacity of system memory: 256GB
- Supports Intel® Extreme Memory Profile (XMP) 3.0x

*1DPC 1R Up to 9066+ MHz (OC), 5600 MHz Natively.
1DPC 2R Up to 6800+ MHz (OC), 5600 MHz Natively.
2DPC 1R Up to 6533+ MHz (OC), 4800 MHz Natively.
2DPC 2R Up to 5600+ MHz (OC), 4400 MHz Natively.

 

[jaydub868]

That board's spec sheet says the following. "Over-clocking" or not, the key words are "up to". Your mileage is unknown until you actually assemble the stuff and see what happens if you attempt to run at higher speeds and face stability issues.

- Dual Channel DDR5 Memory Technology
- 4 x DDR5 DIMM Slots
- Supports DDR5 non-ECC, un-buffered memory up to 9066+(OC)*
- Supports Clocked Unbuffered DIMM (CUDIMM)
- Max. capacity of system memory: 256GB
- Supports Intel® Extreme Memory Profile (XMP) 3.0x

*1DPC 1R Up to 9066+ MHz (OC), 5600 MHz Natively.
1DPC 2R Up to 6800+ MHz (OC), 5600 MHz Natively.
2DPC 1R Up to 6533+ MHz (OC), 4800 MHz Natively.
2DPC 2R Up to 5600+ MHz (OC), 4400 MHz Natively.

So, for 2x16GB dual channel modules, getting memory with a stated rating in excess of 5600 would be unneccesary if I'm to avoid overclocking, correct?

 

[Lafong]

https://www.asrock.com/mb/Intel/Z890 Pro RS WiFi/index.asp#MemoryARLK

Above is the RAM qvl list for that board.

You might want to wait for actual reviews of that board to see how it handles various RAM sticks.

The board should have several "XMP" profiles for speeds above 5600. You could experiment with them as you see fit.

The "sweet spot" for RAM on the current generation Intel boards is supposed to be 6000. It's a near certainty your board would be OK with that.

But it's guesswork until the board and CPU land in the wild and reviews appear. Don't know how quickly you intend to buy.

Here's a link to an explanation of XMP. I don't know what your XMP options will be on that board, maybe several up to and beyond 8000?

Serial presence detect - Wikipedia

en.wikipedia.org

 

[jaydub868]

Thanks a lot. Your help is really appreciated.

 

[CountMike]

So, for 2x16GB dual channel modules, getting memory with a stated rating in excess of 5600 would be unneccesary if I'm to avoid overclocking, correct?

3600MHz is starting point for DDR5 but most usually start at 4133MHz, any higher is considered overclocking , manually or using XMP.

 

[geofelt]

The default speed for DDR5 ram is 4800.
The default voltage is 1.1
Any ram that has speed higher has technically been overclocked and runs at a higher voltage. perhaps as much as 1.4v.
A common confusion in motherboard specs has one speed at which the motherboard will boot into bios where xmp settings can be set to rum at higher(overclocked ) speed.

 

[jaydub868]

The default speed for DDR5 ram is 4800.
The default voltage is 1.1
Any ram that has speed higher has technically been overclocked and runs at a higher voltage. perhaps as much as 1.4v.
A common confusion in motherboard specs has one speed at which the motherboard will boot into bios where xmp settings can be set to rum at higher(overclocked ) speed.

Doesn't "natively" mean not overclocked? My M/B specs state:

1DPC 1R Up to 9066+ MHz (OC), 5600 MHz Natively.

So wouldn't a 5600 stick running at 5600 be not overclocked?

 

[TheHerald]

Doesn't "natively" mean not overclocked? My M/B specs state:

1DPC 1R Up to 9066+ MHz (OC), 5600 MHz Natively.

So wouldn't a 5600 stick running at 5600 be not overclocked?

Ram oc refers to the cpu capabilities not the motherboards. Anything above 5600 on 14th gen is considered an overclock regardless of what your mobo is capable of.

 

[jaydub868]

So, DDR 5600 memory modules running at 5600 is not overclocking relative to a 14th generation CPU. Would the same be considered an overclock relative to DDR5 default frequency of 4800, or would that situation typically not be characterized as such?

 

[CountMike]

So, DDR 5600 memory modules running at 5600 is not overclocking relative to a 14th generation CPU. Would the same be considered an overclock relative to DDR5 default frequency of 4800, or would that situation typically not be characterized as such?

Any IMC frequency over maximum declared by CPU manufacturer is technically overclock.
If for instance IMC=4800MHz. 4801MHz is already OC.

 

[jaydub868]

Any IMC frequency over maximum declared by CPU manufacturer is technically overclock.
If for instance IMC=4800MHz. 4801MHz is already OC.

what is IMC?

 

[CountMike]

what is IMC?

Internal Memory Controller built into CPU. Early systems had it on the motherboard.

 

[jaydub868]

Got it. Someone said that DDR5 memory has a default speed of 4800. Is that really a thing, or are they really referring to the DDR5 speed set in the IMC of a particular CPU?

 

[thestryker]

For Arrow Lake the official specifications are these:

(1DPC/2DPC configuration are referring to 2 slot and 4 slot motherboards)

There are JEDEC memory kits available at each of these types/speeds which will run without changing any settings on the motherboard. Any kit which is XMP instead of JEDEC will require XMP being enabled to run at its rated speed even if it matches the above speeds.

If you're dead set against any memory overclocking this is the fastest kit available and while it's above the specifications for 2DPC it will still run without XMP: https://www.crucial.com/memory/ddr5/ct2k16g64c52cu5

Personally speaking I think getting a DDR5-7200 CL34 kit would be a better idea as it will cost less, should work perfectly fine and be better performance wise.

 

[jaydub868]

Well I was kind of edging to 6000 CL28, but 7200 CL34 sounds pretty good as the speed is essentially the same but the bandwidth is much higher.

 

[jaydub868]

Well I was kind of edging to 6000 CL28, but 7200 CL34 sounds pretty good as the speed is essentially the same but the bandwidth is much higher.

The CAS on that 6400 crucial module is 52...why would it be so high and why would anyone want it?

 

[thestryker]

The CAS on that 6400 crucial module is 52...why would it be so high and why would anyone want it?

JEDEC specifications basically keep very close to the same latency at every speed since DDR4 (4800 is CL40) and this is part of how they can operate at 1.1v while maintaining stability.