answer

[yawehhh]

can you overclock xmp ram in mobo that can only handle 2666mhz?

[Radium_Angel]

2 minutes ago, yawehhh said:

can you overclock xmp ram in mobo that can only handle 2666mhz?

You can overclock anything, if you're good enough.

Whether it's stable is another matter...

[Haro]

if it can handle only up to 2666 

you can't and wont be able to get anything above that.

1 minute ago, Radium_Angel said:

You can overclock anything, if you're good enough.

if the motherboard has a capability of 2666 it wont go above that 

memory overclocking is not the same as cpu overclocking. 

[5x5]

21 minutes ago, yawehhh said:

can you overclock xmp ram in mobo that can only handle 2666mhz?

On AMD, usually yes. On Intel, usually no.