Question Why are XMP profiles different?

[Valcartier]

Hi all,

I recently overclocked my RAM to run at 3600mhz. When in BIOs, only one XMP profile can be selected. Does it matter which one I select?

 

[Eximo]

I'm not sure I understand. If you have overclocked the memory, why would you load an XMP profile? That simply loads whatever memory profile is loaded onto the stick at the factory, which would overwrite your manual settings.

 

[Valcartier]

I'm not sure I understand. If you have overclocked the memory, why would you load an XMP profile? That simply loads whatever memory profile is loaded onto the stick at the factory, which would overwrite your manual settings.

Thank you for your reply. Back in December I posted about RAM performing below expectations, and was told “Your 3600mhz ram is running at 2400mhz. Go into BIOS and enable XMP.”

I may have not properly understood the definition of over clocking. Did I overclock it or what exactly did I do?

 

[Eximo]

XMP is a type of overclocking. It is a faster setting than the JEDEC standard. Which is 2133 for DDR4, and I think it did move to 2400 and eventually 2666 on some platforms.

So if you have a 3600MT/s XMP profile, you can select that one. There may be different sub timings or entire speeds as profiles in a memory kit (Known as SPD)

But you can also manually set each memory timing and sub timing to achieve, potentially, better results than the XMP profiles. The memory manufacturer will have tested those XMP profiles, so they know the memory can do it, but not necessarily with any given CPU/Memory controller.

There is also DOCP and AMP as alternative standards, though they don't come up as much.