Some question about XMP memory's default frequency.

[Karolinska]

Hi.

 

An interesting fact really confused me: The default frequency (1.2V, XMP disabled) of almost all XMP DDR4 memory is 2133Mhz (for instance, my G.Skill 3200Mhz CL14). But there is plenty of non-XMP memory can run at 2666Mhz under 1.2V. So, if high-end XMP memory has selected high quality DRAM chips, why their XMP disabled default frequency is lower than these budget products'?

[knightslugger]

because DDR4 spec is 2133MHz. just about all memory can be overclocked to a degree.

[Klemmbrett]

Why would they do it everybody can select an xmp profile which fits their needs some CPU/Board´s will not support higher than 2400 for example. So its mainly compatibility.  A K CPU also does not come tuned out of the box and will work in a non Z board because of this. You could argue that people will have Hardware that fits the need of this RAM but its nothing you can take for granted maybe some casemodder want´s the look of a nice high end RGB ram for their theme but have low end hardware because its only a nice look build except for the RAM. And most people that invest in such RAM will spend some time in BIOS anyway to tune their processor so its no problem for them to do 1 click to select a desiered XMP profile.    

[G27Racer_188]

Because 2133 is like guaranteed^TM speed that will work on every motherboard.

[Princess Luna]

Most chipsets use either 2133mhz or 2400mhz base frequency, so until you active the XMP profile successfully any memory will run at it.

 

This is because setting a base standard makes troubleshooting and making it stable much easier alongside the simple fact not all modules may even function on a higher frequency than that in the first place.

[Karolinska]

2 minutes ago, Klemmbrett said:

Why would they do it everybody can select an xmp profile which fits their needs some CPU/Board´s will not support higher than 2400 for example. So its mainly compatibility.  A K CPU also does not come tuned out of the box and will work in a non Z board because of this. You could argue that people will have Hardware that fits the need of this RAM but its nothing you can take for granted maybe some casemodder want´s the look of a nice high end RGB ram for their theme but have low end hardware because its only a nice look build except for the RAM. And most people that invest in such RAM will spend some time in BIOS anyway to tune their processor so its no problem for them to do 1 click to select a desiered XMP profile.    

Thanks for replying my noob question. But… We can still use native 2400/2666Mhz non-XMP memory on budget Skylake platform like H110, and it will run at 2133Mhz perfectly, so why these high-end memory choose 2133Mhz as their default?

[Tech Wizard]

Just now, Karolinska said:

Thanks for replying my noob question. But… We can still use native 2400/2666Mhz non-XMP memory on budget Skylake platform like H110, and it will run at 2133Mhz perfectly, so why these high-end memory choose 2133Mhz as their default?

Some motherboards applies the correct XMP profile for the rated speed of the DIMMS, while some motherboards only does the default speed of DDR3/DDR4(1333/2133MHz) and you have to change to the XMP profile urself.

[Karolinska]

10 minutes ago, Tech Wizard said:

Some motherboards applies the correct XMP profile for the rated speed of the DIMMS, while some motherboards only does the default speed of DDR3/DDR4(1333/2133MHz) and you have to change to the XMP profile urself.

So, it's possible for me to manually tune the RAM working at 2666Mhz+ under 1.2V even it's not a preload XMP profile?

[knightslugger]

Just now, Karolinska said:

So, it's possible for me to manually tune the RAM working at 2666Mhz+ under 1.2V even it's not a preload XMP profile?

yup. though your experience and gains will vary. if you don't know what you're doing, i'd stop while you're ahead.

[Karolinska]

2 minutes ago, knightslugger said:

yup. though your experience and gains will vary. if you don't know what you're doing, i'd stop while you're ahead.

Thanks for replying. I'm just wondering: If I going to take some serious heavy loaded works with my PC (like temporarily as a remote server), do under-voltage the memory from 1.35V to 1.2V helps to increase the stability? Or keeping the factory XMP profile is enough? I have doubt on this because I find pre-built workstations (like Dell Precision) never use high frequency XMP memory.