Will my ram be bottlenecked + XMP

[nexroid]

Basically my friend has a mobo that has a max of 2133mhz ram, and ram that is 2666, its 8gb. Will this bottleneck make a huge difference/ any difference at all to gaming or general use? In addition to this "bottleneck" he also says that XMP makes a huge difference to his gaming performance and complains constantly that he doesnt have it. Does xmp make a huge difference to gaming preformance?

 

[clutchc]

No to both questions. The difference between 2133mhz DDR3 and 2666mhz DDR3 is negligible. And XMP is simply a 'profile' to make it easier for the user to get memory to run at its rated clock speed. The profile doesn't improve performance. The change in mhz might.