well the spike might change depending on number of ppl online (whish agaiin is a higher chance of some1 making 1) but most time i experiance some1 making a guild i see somewhere between a 10min+ spike if we talk 15~21 gmt+1 time (what i usually call rush hour =/)
but well figured i would suggest what i could to reduce it ^^
Edit:
well ill keep looking for ways to help out :3