I would like to know how long it takes for a General computer based GRE score to be delivered to graduate school in US. Some graduate schools mention do not take GRE later than specific date so I am wondering does it really take long time to send the score online?
Per the ETS website, for the online general GRE (emphasis mine):
About 10–15 days after your test date, your official scores will be available in your My GRE Account, and your scores will be sent to the score recipients you designate
It is up to the receiving institution to decide how they want to receive those scores: online (which doesn't add additional delivery time), or paper mail (which adds some additional shipping time).